Method and device for detecting corrosion resistance of battery terminals

Abstract

The application belongs to the field of photovoltaic cells, and specifically discloses a detection method and device for corrosion resistance of cell terminals. The application takes the change rate of the electrical performance of a cell terminal assembly that has passed the standard damp-heat test under a simulated damp-heat environment as a benchmark, replaces the flux and / or adhesive film in a reference cell terminal assembly, obtains a cell terminal assembly to be tested, and then obtains the change rate of the electrical performance of the cell terminal assembly to be tested under the simulated damp-heat environment. A comparison between the two change rates can obtain the corrosion resistance of the cell terminal assembly to be tested, and whether the cell and the adhesive film or / and the flux are suitable can be determined according to the corrosion resistance of the cell terminal assembly. The first aspect of the application directly uses the flux and / or the adhesive film to conduct the test, so that the simulated damp-heat reaction is closer to the actual situation, and the result obtained by the test is more accurate for guiding the actual situation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic cells, in particular to a method and device for detecting corrosion resistance of cell end. BACKGROUND

[0002] Photovoltaic modules often face harsh environments such as high temperature and high humidity during use. Under the action of temperature and humidity, the encapsulation film in the module and the flux introduced in the process may react with the surface of the cell, thereby causing corrosion of the cell, and ultimately leading to performance degradation of the module. As the structure of the cell develops, the composition of the paste, flux and film becomes more complex, and it is more important to evaluate the corrosion resistance of the cell and the reliability of the module.

[0003] Currently, when photovoltaic module manufacturers introduce films or fluxes from different manufacturers, they must first prepare complete modules and then conduct long-term damp heat aging tests for several months to evaluate the compatibility between new supplies and cells. The test period is long and the cost is high. From the cell end, a single acetic acid test is often used to evaluate the corrosion resistance of the cell, which cannot truly reflect the influence of the film composition on the cell, and the corrosion resistance conclusion obtained is unreliable. SUMMARY

[0004] The present application aims to at least partially solve one of the above technical problems. To this end, one object of the present application is to propose a method and device for detecting corrosion resistance of cell end.

[0005] A first aspect of the present application provides a method for detecting corrosion resistance of cell end, comprising the following operations:

[0006] conducting an aging test on a reference cell end module in a simulated damp heat environment to obtain a change rate of electrical performance parameters of a first cell in the reference cell end module as a benchmark change rate of electrical performance parameters; wherein the reference cell end module comprises a first cell, a first flux and a first film, the first flux is coated on the grid line area of the first cell, and the first film covers one side of the first cell close to the grid line area by pressure;

[0007] The photovoltaic module in which the same cell end module as the reference cell end module is located has passed the standard damp heat test;

[0008] providing a cell end module to be tested, the cell end module to be tested comprising a second cell, a second flux and a second film; wherein the second flux is coated on the grid line area of the second cell, and the second film covers one side of the second cell close to the grid line area by pressure;

[0009] The second cell is another cell identical to the first cell;

[0010] placing the battery end assembly to be tested in the simulated humid heat environment for aging, and then obtaining the change rate of the electrical performance parameter of the second battery sheet;

[0011] According to the change rate of the electrical performance parameter of the second battery sheet and the reference change rate of the electrical performance parameter, the corrosion resistance of the battery end assembly to be tested is evaluated.

[0012] The first aspect of the present application takes the change rate of the electrical performance of the battery end assembly in the simulated humid heat environment as a reference, replaces the flux and / or the adhesive film in the reference battery end assembly with the battery end assembly to be tested, and then obtains the change rate of the electrical performance of the battery end assembly to be tested in the simulated humid heat environment. The corrosion resistance of the battery end assembly to be tested can be obtained by comparing the two change rates. The corrosion resistance of the battery end assembly can be used to determine whether the battery sheet and the adhesive film or / and the flux are suitable. The first aspect of the present application directly uses the flux and / or the adhesive film for testing, so that the simulated humid heat reaction is more close to the actual situation, and the result obtained by the test is more accurate.

[0013] The second aspect of the present application provides a device for detecting the corrosion resistance of a battery end, which comprises a platform, a release film and a pressurizing weight.

[0014] The release film and the pressurizing weight are respectively provided with first through holes;

[0015] When the corrosion resistance of the battery end assembly is detected, the battery end assembly is located on the platform, the release film and the pressurizing weight are located above the battery end assembly, and the side of the battery end assembly close to the release film can be connected to the outside through the first through holes.

[0016] Therefore, the corrosion resistance of the battery end assembly is facilitated.

[0017] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings, wherein:

[0019] Figure 1 is a flowchart according to some embodiments of the present application;

[0020] Figure 2 is a structural schematic diagram according to some embodiments of the present application.

[0021] REFERENCE NUMERALS:

[0022] 1 - platform; 2 - battery sheet; 3 - adhesive film; 4 - release film; 5 - pressurizing weight. Detailed Implementation

[0023] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0024] Currently, acetic acid testing is often used to evaluate the corrosion resistance of solar cells because ethylene-vinyl acetate copolymer (EVA) hydrolysis produces acetic acid. However, the composition of the encapsulant film is becoming increasingly complex, and the current evaluation method cannot actually reflect the impact of the complex composition of the encapsulant film on the solar cell. In addition, polyolefin elastomer (POE) encapsulants theoretically do not produce acetic acid, but they also face the problem of failure, which further illustrates the limitations of the acetic acid test.

[0025] An embodiment of the first aspect of this application provides a method for detecting the corrosion resistance of a battery terminal.

[0026] In some embodiments, see Figure 1 , Figure 1 A flowchart of a method for testing the corrosion resistance of battery terminals, including the following steps:

[0027] S1. An aging test is performed on the reference battery terminal assembly in a simulated humid and hot environment to obtain the rate of change of electrical performance parameters of the first battery cell in the reference battery terminal assembly, which is used as the reference rate of change of electrical performance parameters; wherein, the reference battery terminal assembly includes a first battery cell, a first flux and a first adhesive film, the first flux is coated on the grid line area of ​​the first battery cell, and the first adhesive film is covered on the side of the first battery cell near the grid line area by pressure.

[0028] The photovoltaic module containing the same battery terminal as the reference battery terminal has passed the standard damp heat test.

[0029] S2. Provide a battery terminal assembly to be tested, which includes a second battery cell, a second flux, and a second adhesive film; wherein, the second flux is coated on the grid line area of ​​the second battery cell, and the second adhesive film covers the side of the second battery cell near the grid line area by pressure;

[0030] The second battery cell is another battery cell that is the same as the first battery cell;

[0031] The battery terminal assembly to be tested was placed in the simulated humid and hot environment for aging, and then the rate of change of the electrical performance parameters of the second battery cell was obtained.

[0032] S3, according to the change rate of the electrical performance parameter of the second cell and the reference change rate of the electrical performance parameter, evaluate the corrosion resistance of the battery end assembly to be tested.

[0033] In a specific production scenario, photovoltaic modules of the same specification are generally produced in batches by a production line. The products (photovoltaic modules) of the same batch and the same specification are basically the same in all aspects of performance. When performing the test, one or more products can be selected from the products of the same batch to perform the standard damp-heat test. When the one or more products pass the standard damp-heat test and are identified as qualified, it is identified that the battery end assembly in the batch of products is also qualified. At this time, the battery end assembly in one photovoltaic module can be selected from the products of the batch as a reference battery end assembly. The reference battery end assembly is subjected to the aging test, and the change rate of the electrical performance parameter obtained by the aging test is taken as the reference change rate of the electrical performance parameter, which is used as a reference to evaluate the corrosion resistance of other cells.

[0034] The embodiments of the first aspect of the present application evaluate the corrosion resistance of the battery end assembly, and the corrosion degree of the cell caused by the adhesive film and the flux can be accurately and quickly evaluated before the photovoltaic module is packaged, so that the corrosion resistance of the battery end can be evaluated. Unlike the use of acetic acid test or acetic acid and flux superposition test alone to evaluate the corrosion resistance of the battery end, the embodiments of the first aspect of the present application apply the flux to the grid line area of the cell, then cover the adhesive film on the surface of the cell, and then apply pressure on the adhesive film to obtain a laminated piece to simulate the condition of the battery end assembly in the real photovoltaic module. Then, the laminated piece is placed in a simulated damp-heat environment for aging treatment, and the aged battery end assembly can be obtained. As can be seen from the above, the first aspect of the present application directly uses the adhesive film or / and the flux to perform the test, and the test result is closer to the real situation. In addition, the reference change rate of the electrical performance parameter of the first aspect of the present application is more reasonable. The photovoltaic module that passes the standard damp-heat test indicates that the matching in the photovoltaic module meets the corrosion resistance. The same battery end assembly as that in the photovoltaic module is taken as a reference battery end assembly to be aged in a simulated damp-heat environment. The change rate of the electrical performance before and after aging is tested, and the reference change rate of the electrical performance parameter is obtained. The simulated damp-heat environment is an accelerated process of natural damp-heat aging. In the simulated damp-heat environment, the physicochemical reactions of the battery end assembly and the natural damp-heat aging occur at the same time, but the reaction speed is accelerated. Therefore, the corrosion resistance result obtained by accelerating the aging based on the simulated damp-heat environment can guide the actual situation, and can indicate whether the cell and the adhesive film or / and the flux are suitable.

[0035] It can be understood that the second cell in the above embodiments is the same as the first cell, which means that the two are selected from the same specification. For example, they can be selected from the same specification of emitter and back surface passivation cells.

[0036] It is worth mentioning that the first battery piece in S1 can be one of a crystalline silicon battery piece, a perovskite battery piece, or a stack of the two. Thus, the detection method for the corrosion resistance of the battery end has a wide range of applications. Further, the crystalline silicon battery piece includes, but is not limited to, an emitter and back passivation battery piece (PERC battery piece), a tunnel oxide passivation contact solar cell (TOPCon battery piece), a TOPCon superimposed back electrode contact battery piece (TBC battery piece), a heterojunction battery piece (HJT battery piece), or a back contact heterojunction battery piece (HBC battery piece).

[0037] In some embodiments, the standards in S1 include the DH 1000 damp heat aging test of the IEC 61730 standard and the DH 1000 damp heat aging test of the IEC 61215 standard. Thus, the above standards can be tested alternatively or both standards can be tested.

[0038] In some embodiments, in S1, the simulated damp heat environment includes a temperature of 90-160°C, a relative humidity of 60-100%, and a time of 6-24h. For example, the temperature can be 90°C, 120°C, 150°C, 160°C, etc.; the relative humidity can be 60-100%, 60%, 80%, 100%, etc.; and the time can be 6h, 12h, 20h, 24h, etc. Thus, the high temperature and high humidity conditions are set to accelerate the aging test, wherein the temperature range includes the high temperature environment that the photovoltaic module may face in subsequent processes and use, such as lamination temperature, hot spot caused local high temperature environment, etc., and the relative humidity range includes common humidity and water surface high humidity environment. The setting of the simulated damp heat environment is more close to the actual situation, and the results obtained are more capable of guiding the actual arrangement.

[0039] In some embodiments, in S2, at least one of the second flux and the second adhesive film is different from that of the reference battery end assembly. For example, the second flux is different from the first flux, and the corrosion resistance of the battery end assembly to be tested is used to illustrate the adaptability between the second battery piece and the second flux; for another example, the second adhesive film is different from the first adhesive film in the reference battery end assembly, and the corrosion resistance of the battery end assembly to be tested is used to illustrate the adaptability between the second battery piece and the second adhesive film; for another example, the second flux is different from the first flux, and the second adhesive film is different from the first adhesive film, and the corrosion resistance of the battery end assembly to be tested is used to illustrate the adaptability of the battery piece to the second adhesive film and the second flux.

[0040] In some embodiments, in S1 and S2, the first adhesive film and the second adhesive film are respectively independently subjected to the following treatment: at a temperature of 80-90°C, under a pressure of 0.1-1 MPa, for 2 min or more. For example, the temperature is 80°C, 85°C, 90°C, etc., the pressure is 0.2 MPa, 0.5 MPa, 1 MPa, etc., and the treatment time is 2 min, 3 min, 4 min, 5 min, etc. Alternatively, the treatment time is 2-5 min. In this way, the first adhesive film and the second adhesive film are pretreated to have a more flat surface and better adhere to the corresponding battery piece. Further, a release film is placed on both sides of the adhesive film during the treatment to facilitate release. The release film can be at least one of a polyester (PET) film and a polyethylene (PE) film.

[0041] In some embodiments, in S1 and S2, the first pressure applied by the first adhesive film and the second pressure applied by the second adhesive film are respectively independently 0.05-0.5 MPa, for example, 0.05 MPa, 0.1 MPa, 0.25 MPa, 0.5 MPa, etc. In this way, the lamination pressure of the reference battery end assembly and the battery end assembly to be tested in the corresponding photovoltaic assembly is better simulated, and the adhesive film adheres better to the battery piece.

[0042] In some embodiments, in S1 and S2, the means for obtaining the rate of change of the electrical performance parameter of the battery piece in the battery end assembly can include peeling the adhesive film and the battery piece apart, and the peeling means can be: using negative pressure to adsorb the battery piece away from one side of the adhesive film, then using a hot air gun to heat the side of the adhesive film away from the battery piece, and then peeling the adhesive film and the battery piece apart. It should be noted that in S1, the above adhesive film and battery piece refer to the first adhesive film and the first battery piece; in S2, the above adhesive film and battery piece refer to the second adhesive film and the second battery piece. In this way, the influence of peeling on the corresponding battery piece is reduced, and the electrical performance parameters of the aged battery piece are conveniently tested.

[0043] In some embodiments, in S1 and S2, the rate of change of the electrical performance parameter includes the maximum output power, i.e., the maximum output power of the battery piece measured using an FCT650 instrument under standard electrical performance test conditions. Compared to testing the contact resistance, which only reflects the corrosion of the metal grid area of the battery piece, the maximum output power as a comprehensive parameter can more comprehensively reflect the corrosion resistance of the battery piece. Since the first aspect of the present application uses an adhesive film or / and a flux as a raw material, the corrosion is not limited to acetic acid corrosion, and the corrosion area is not limited to the metal grid area of the battery piece. Therefore, in the case of using the contact resistance as an index to reflect the distortion of the corrosion resistance of the battery end assembly, the maximum output power still has high accuracy.

[0044] In some embodiments, in S3, corrosion resistance of the battery end assembly to be tested is evaluated according to the change rate of the electrical performance parameter of the second battery piece and the reference change rate of the electrical performance parameter. It can be understood that the greater the change rate of the electrical performance parameter, the worse the corrosion resistance. Therefore, in the case that the change rate of the electrical performance parameter is not greater than the reference change rate of the electrical performance parameter, the corrosion resistance of the battery end is evaluated as qualified, otherwise, as unqualified. Thus, the corrosion resistance of the battery end to be tested is evaluated.

[0045] In some embodiments of the second aspect of the present application, a device for detecting corrosion resistance of a battery end is provided.

[0046] In some embodiments, referring to Figure 2 A device for detecting corrosion resistance of a battery end includes a platform 1, a release film 4 and a pressurizing weight 5. The release film 4 and the pressurizing weight 5 are both provided with first through holes. When testing the corrosion resistance of a battery piece 2, the battery piece 2 is placed on the platform 1, and a soldering flux and a film 3 are provided above the battery piece 2. The release film 4 and the pressurizing weight 5 are provided on the side of the film 3 away from the battery piece 2, and the side of the battery piece close to the release film 4 can be connected to the outside through the first through holes. Thus, the presence of the release film 4 avoids strong adhesion caused by direct contact between the pressurizing weight 5 and the film 3, and the first through holes serve as a path for water vapor to enter the surface of the film, simulating the actual working condition of the assembly.

[0047] Further, in the device for detecting corrosion resistance of a battery end, the platform 1 can be a cubic platform with vertical through holes, and the platform 1 can be made of at least one of polytetrafluoroethylene, polyvinylidene fluoride and other corrosion-resistant materials. Thus, the battery piece can be easily placed without affecting the results during the aging process.

[0048] Further, in the device for detecting corrosion resistance of a battery end, the pressurizing weight 5 is a cubic weight, and the first through holes on the pressurizing weight 5 are uniformly distributed vertical through holes. Thus, the pressure is uniform.

[0049] Optionally, the cross-sectional area of the first through holes on the pressurizing weight 5 and the release film 4 is independently 40mm 2 ~ 80mm 2 , preferably 60mm 2 . Further, the distribution density of the first through holes on the pressurizing weight 5 and the release film 4 is independently greater than or equal to 1 per square centimeter. Thus, it is more conducive for water vapor to enter the battery piece assembly through the first through holes.

[0050] In some embodiments, in the battery end corrosion resistance detection device, the platform 1 is provided with a second through hole, which provides a negative pressure channel for the side close to the battery piece. Thus, the second through hole of the platform 1 facilitates the subsequent use of a vacuum pump to generate negative pressure, tightly suck the battery piece, and facilitate the peeling of the adhesive film and the battery piece without damaging the battery piece.

[0051] Optionally, the cross-sectional area of the second through hole can be between 1mm 2 ~ 10mm 2 , preferably 2mm 2 . Further, the distribution density of the second through hole is greater than or equal to 4 per square centimeter, for example, 4 per square centimeter ~ 10 per square centimeter. Thus, the negative pressure channel is more intensive, and the adsorption area is small, providing stronger adsorption force for the battery piece assembly.

[0052] Optionally, in the battery end corrosion resistance detection device, the second through hole can be a vertical through hole. Thus, the negative pressure channel is shorter and easier to generate negative pressure.

[0053] The present application will be described below with reference to specific embodiments, which should be illustrative only, and not in any way limit the present application.

[0054] Embodiment 1

[0055] Take 210R-TOPCon battery piece, Tongfang TFHF9100 flux, and Swick SV-15296P adhesive film as the battery end assembly to be tested, including the following operations:

[0056] Step 1: Obtain the reference maximum output power change rate △P0 of the reference battery end assembly, specifically:

[0057] Provide a standard photovoltaic module that meets the requirements of the damp heat test, which includes 210R-TOPCon battery piece, Foster TF4-N adhesive film, and Wilks WS-868 flux;

[0058] Stack 210R-TOPCon battery piece, Wilks WS-868 flux, and Foster TF4-N adhesive film, and apply a pressure of 0.5MPa on the Foster TF4-N adhesive film as a reference battery end assembly; age the reference battery end assembly in a simulated damp heat environment with a temperature of 140℃, a relative humidity of 85%, and a time of 6h, to obtain the maximum output power change rate of the 210R-TOPCon battery piece as the reference maximum output power change rate △P0;

[0059] Step 2: Use the corrosion resistance detection device to detect the corrosion resistance of the battery end assembly to be tested

[0060] The corrosion-resistant detection device comprises a cubic platform 1 provided with a second through hole; a release film 4 and a pressurizing weight 5, both of which are provided with a first through hole. The platform 1 is made of polytetrafluoroethylene corrosion-resistant material;

[0061] Place the 210R-TOPCon cell on the platform 1, and apply the flux of Tongfang TFHF9100 with a concentration of 35% on the grid line area of the 210R-TOPCon cell.

[0062] Step 3: Place the Swagelok SV-15296P film with the same size as the 210R-TOPCon cell on the 210R-TOPCon cell coated with the flux of Tongfang TFHF9100.

[0063] Step 4: Place the release film 4 on the Swagelok SV-15296P film, and place the pressurizing weight 5 on the release film 4, and the first through holes of the two are connected to the outside.

[0064] Step 5: Place the above-mentioned whole in a high-temperature and high-humidity environment box for aging treatment, set the temperature to 140℃, the relative humidity to 85%, and the time to 6h.

[0065] Step 6: After the aging test is completed, remove the pressurizing weight 5 and the release film 4 from the high-temperature and high-humidity environment box, then connect the second through hole of the platform 1 to the vacuum pump to tightly suck the 210R-TOPCon cell, heat the upper surface of the Swagelok SV-15296P film with a hot air gun, then peel off the Swagelok SV-15296P film and the 210R-TOPCon cell, test the maximum output power of the 210R-TOPCon cell, and obtain the maximum output power change rate ΔP of the 210R-TOPCon cell.

[0066] Example 2

[0067] The other steps are the same as those in Example 1, except that the Velsicol WS-868 flux is applied in step (2).

[0068] Example 3

[0069] The other steps are the same as those in Example 1, except that the Swagelok TF4-N film is placed in step (3).

[0070] Comparative Example 1

[0071] The other steps are the same as those in Example 1, except that the reference cell end assembly film in step (1) and the film in step (3) are replaced with acetic acid applied on the grid line area of the 210R-TOPCon cell.

[0072] Comparative Example 2

[0073] Other than the same as example 1, the difference is that the maximum output power change rate of the battery end assembly is obtained in steps (1) and (6) instead of the contact resistance change rate of the battery end assembly.

[0074] Test analysis

[0075] The FCT650 instrument is used to measure the maximum output power of the battery sheet before and after aging in examples 1-3 and comparative example 1, and the maximum output power change rate is calculated based on the maximum output power before and after aging. The contact resistance of the battery sheet before and after aging is measured by the transmission line model (TLM) method in comparative example 2, and the contact resistance change rate is calculated based on the contact resistance before and after aging. Then the battery sheet, flux and adhesive film involved in example 1, example 2, example 3, comparative example 1 and comparative example 2 are assembled into photovoltaic modules, and the maximum output power of the photovoltaic modules before and after aging is measured according to the DH 1000 damp heat aging test of IEC 61215 standard, and the maximum output power change rate is obtained. The upper limit of the maximum output power change rate under this standard is 5%, and no more than 5% is passed, otherwise it is not passed. The specific data is shown in Table 1.

[0076] Table 1

[0077]

[0078] Note: △R0 is the reference contact resistance change rate; △R is the contact resistance change rate; △P0 is the reference maximum output power change rate; △P is the maximum output power change rate.

[0079] As can be seen from Table 1, the △P of example 1 is 4.4%, which is higher than the 3.5% of the △P0, proving that the battery sheet is not suitable for the Swick SV-15296P adhesive film and the Tongfang TFHF9100 flux, and the corrosion resistance is not good. In order to further verify this conclusion, the photovoltaic module made of the above battery sheet, flux and adhesive film is used for IEC standard damp heat test, and the maximum output power loss is 7.2% after DH 1000, which does not pass the damp heat test evaluation, which is consistent with the results of the detection method proposed in this application.

[0080] The △P of example 2 is 4.2%, which is higher than the 3.5% of the △P0, proving that the battery sheet is not suitable for the Swick SV-15296P adhesive film and the Wilsa WS-868 flux, and the corrosion resistance is not good. The photovoltaic module made of the above battery sheet, flux and adhesive film is sent to IEC standard damp heat test, and the maximum output power loss is 5.4% after DH 1000, which does not pass the damp heat test evaluation, which is consistent with the results of the detection method proposed in this application.

[0081] The ΔP of Example 3 is 1.5%, which is lower than 3.5% of ΔP0. It is proved that the battery piece is suitable for Foster TF4-N adhesive film and Tongfang TFHF9100 flux, and has good corrosion resistance. The module made by using the above battery piece, flux and adhesive film passes the IEC standard damp heat test, and the maximum output power loss of DH1000 is 2.2%, which is consistent with the results of the detection method proposed in the application.

[0082] The ΔP of Comparative Example 1 is 2.6%, which is lower than 3.0% of ΔP0. It is concluded that the battery end has good corrosion resistance, but the maximum output power loss of the module after DH1000 is 7.1%, which is higher than 5% of the IEC standard, and the photovoltaic module does not pass the damp heat test evaluation. It is proved that the use of acetic acid test to evaluate the corrosion resistance of the battery piece cannot truly reflect the influence of the adhesive film composition on the battery piece, and the obtained corrosion resistance conclusion is unreliable.

[0083] The ΔR of Comparative Example 2 is 39%, which is lower than 45% of ΔR0. The contact resistance change value is less than the reference contact resistance change value, but the photovoltaic module does not pass the damp heat test evaluation. It is proved that the method of judging the corrosion resistance of the battery end by the contact resistance is not accurate.

[0084] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0085] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for detecting the corrosion resistance of battery terminals, characterized in that, Includes the following operations: An aging test is conducted on a reference battery terminal assembly in a simulated damp heat environment to obtain the rate of change of electrical performance parameters of the first cell in the reference battery terminal assembly, which is used as a baseline rate of change of electrical performance parameters. The reference battery terminal assembly includes a first cell, a first flux, and a first encapsulant film. The first flux is coated on the grid area of ​​the first cell, and the first encapsulant film is covered on the side of the first cell near the grid area by a first pressure. The photovoltaic module containing the same battery terminal assembly as the reference battery terminal assembly has passed standard damp heat testing. A battery terminal assembly to be tested is provided, the battery terminal assembly to be tested including a second battery cell, a second flux, and a second adhesive film; wherein, the second flux is coated on the grid line area of ​​the second battery cell, and the second adhesive film covers the side of the second battery cell near the grid line area by a second pressure; the second battery cell is another battery cell identical to the first battery cell; The battery terminal assembly to be tested was placed in the simulated humid and hot environment for aging, and then the rate of change of the electrical performance parameters of the second battery cell was obtained. The corrosion resistance of the battery terminal assembly under test is evaluated based on the rate of change of the electrical performance parameters of the second battery cell and the rate of change of the reference electrical performance parameters. The rate of change of the electrical performance parameters includes the maximum output power.

2. The method for detecting the corrosion resistance of battery terminals according to claim 1, characterized in that, The standards for the standard damp heat test include: DH 1000 damp heat aging test according to IEC 61730 standard; DH 1000 damp heat aging test according to IEC61215 standard.

3. The method for detecting the corrosion resistance of battery terminals according to claim 1, characterized in that, The second flux is different from the first flux; And / or, the second adhesive film is different from the first adhesive film.

4. The method for detecting the corrosion resistance of battery terminals according to claim 1, characterized in that, The simulated hot and humid environment includes a temperature of 90℃ to 160℃, a relative humidity of 60% to 100%, and a duration of 6 h to 24 h.

5. The method for detecting the corrosion resistance of battery terminals according to claim 1, characterized in that, The first pressure and the second pressure are each independently 0.05 MPa to 0.5 MPa.

6. The method for detecting the corrosion resistance of battery terminals according to claim 1, characterized in that, The first adhesive film and the second adhesive film are each independently subjected to the following treatment: Treat for more than 2 minutes at a temperature of 80℃~90℃ and a pressure of 0.1 MPa~1 MPa.

7. The method for detecting the corrosion resistance of battery terminals according to any one of claims 1 to 6, characterized in that, The corrosion resistance of the battery terminal assembly under test is evaluated based on the rate of change of the electrical performance parameters of the second battery cell and the rate of change of the baseline electrical performance parameters, including: When the rate of change of the electrical performance parameters of the second battery cell is not greater than the rate of change of the reference electrical performance parameters, the corrosion resistance of the battery terminal assembly under test is evaluated as qualified. Otherwise, the corrosion resistance of the battery terminal component under test is deemed unqualified.

8. The method for detecting the corrosion resistance of battery terminals according to any one of claims 1 to 6, characterized in that, The first solar cell is a stack of one or both of crystalline silicon solar cells and perovskite solar cells.

9. The method for detecting the corrosion resistance of battery terminals according to claim 8, characterized in that, The crystalline silicon solar cell includes an emitter and back passivated solar cell, a tunnel oxide passivated contact solar cell, a TOPCon stacked back electrode contact cell, a heterojunction solar cell, or a back contact heterojunction solar cell.

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