Humidity-sensitive color-changing composition and application thereof

Abstract

The invention relates to a humidity-sensitive color-changing composition and application thereof. The humidity-sensitive color-changing composition comprises a humidity-sensitive color-changing material and a conductive agent, wherein the humidity-sensitive color-changing material comprises a color-changing agent and a color-developing agent in a mass ratio of (1-1.5): (100-105); wherein when the humidity is greater than or equal to a preset value, the color developing agent can provide protons or receive electrons to change the color of the color changing agent. The humidity-sensitive color-changing composition can be applied to battery slurry, the condition that a photovoltaic module is affected by humidity due to the slurry in a solar battery is visually fed back through reversible color change on the premise that the conductivity and the reliability of the battery slurry are not affected, and the slurry improvement effect is better judged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solar cells, in particular to a humidity-sensitive color-changing composition and application thereof. BACKGROUND

[0002] With the development of solar cell technology, photovoltaic modules have been more and more widely used. However, photovoltaic modules are still susceptible to humidity, which leads to power attenuation. Specifically, the power of photovoltaic modules is affected by the corrosion of grid lines made of cell paste, and the power of photovoltaic modules is also affected by the materials of encapsulation adhesive film and glass. Both of them usually exist at the same time. Researchers improve the power attenuation of photovoltaic modules caused by humidity by optimizing the composition of cell paste. However, the improvement effect of the paste is currently judged by indoor DH (damp heat) test. Specifically, the improvement effect of the paste is judged by comparing EL test (electroluminescence detection) data and module electrical performance parameters under damp heat conditions. However, the fluctuation of adhesive film and glass materials and unstable process control can affect the EL test results and module electrical performance parameters, thereby affecting the judgment of the improvement effect of the paste. SUMMARY

[0003] Therefore, some embodiments of the present application provide a humidity-sensitive color-changing composition which can be applied in cell paste. Under the premise of not affecting the conductivity and reliability of the paste, the humidity-sensitive color-changing composition can intuitively feedback the situation of photovoltaic modules affected by humidity caused by the paste itself in solar cells through reversible color change, and better judge the improvement effect of the paste.

[0004] In addition, some other embodiments of the present application also provide an application of the humidity-sensitive color-changing composition.

[0005] A humidity-sensitive color-changing composition includes a humidity-sensitive color-changing material and a conductive agent, and the humidity-sensitive color-changing material includes a color-changing agent and a color-developing agent with a mass ratio of (1-1.5):(100-105).

[0006] When the humidity is greater than or equal to a preset value, the color-developing agent can provide protons or accept electrons to change the color of the color-changing agent.

[0007] In some embodiments, the color-changing agent includes an acid-base indicator.

[0008] In some embodiments, the color-changing agent includes one or more of p-cresol red, thymol blue, litmus, phenothalin, thymolphthalein, phenol red, neutral red, malachite green, methyl red, methyl violet, methyl orange, methyl green, dimethyl yellow, bromothymol blue, bromophenol blue, dimethylphenol blue, methylene blue, azo red, azo yellow, azo orange, congo red, bromophenol red, bromocresol green, bromocresol purple, fast yellow, alizarin red S, and alizarin yellow R.

[0009] In some embodiments, the color-changing agent comprises one or more of p-cresol red and thymol blue.

[0010] In some embodiments, the color-developing agent comprises one or more of an acidic reagent and a basic reagent.

[0011] In some embodiments, the color-developing agent comprises one or more of boric acid, sulfuric acid, nitric acid, citric acid, acetic acid, sodium hydroxide and potassium hydroxide.

[0012] In some embodiments, the moisture-sensitive color-changing material further comprises a hygroscopic agent, and the mass ratio of the hygroscopic agent to the color-changing agent is (140-150):(1-1.5).

[0013] In some embodiments, the hygroscopic agent comprises one or more of silica gel, activated carbon, molecular sieve, bentonite, ethylene glycol, glycerol, xylitol, mannitol and sorbitol.

[0014] In some embodiments, the mass ratio of the moisture-sensitive color-changing material to the conductive agent is 16:(3-8).

[0015] In some embodiments, the mass ratio of the moisture-sensitive color-changing material to the conductive agent is 16:(5-5.5).

[0016] In some embodiments, the conductive agent comprises one or more of silver nanoparticles, gold nanoparticles and antimony tin oxide.

[0017] In some embodiments, the moisture-sensitive color-changing composition further comprises a binder, and the mass ratio of the binder to the moisture-sensitive color-changing material is (1.5-3):16.

[0018] In some embodiments, the binder comprises one or more of polyvinyl alcohol, sodium carboxymethyl cellulose and sodium polyacrylate.

[0019] In some embodiments, the moisture-sensitive color-changing composition further comprises a dispersant, and the mass ratio of the dispersant to the moisture-sensitive color-changing material is (1-1.5):16.

[0020] In some embodiments, the dispersant comprises one or more of polyvinylpyrrolidone and sodium dodecyl sulfate.

[0021] Use of the moisture-sensitive color-changing composition as described above in the preparation of a solar cell paste.

[0022] A solar cell paste comprising the moisture-sensitive color-changing composition as described above and a base paste.

[0023] In some embodiments, the mass ratio of the humidity-sensitive color-changing composition and the base paste is 1: (20-40).

[0024] A solar cell includes a substrate and a grid line formed on a surface of the substrate, the grid line being prepared by the solar cell paste described above.

[0025] A photovoltaic module includes the solar cell described above, an encapsulation adhesive film disposed on a surface of the solar cell, and a cover plate disposed on a surface of the encapsulation adhesive film away from the solar cell.

[0026] A method for testing the moisture resistance of a solar cell paste includes the following steps:

[0027] A grid line of a photovoltaic module is prepared using the solar cell paste described above.

[0028] The photovoltaic module is placed in a predetermined humidity environment, and the moisture resistance of the solar cell paste is determined according to the color of the grid line in the photovoltaic module.

[0029] A method for monitoring the failure of a photovoltaic module includes the following steps:

[0030] Color information of a photovoltaic module is obtained, the photovoltaic module being as described above.

[0031] The failure of the photovoltaic module is monitored according to the color information.

[0032] The humidity-sensitive color-changing composition of some embodiments of the present application includes a humidity-sensitive color-changing material and a conductive agent. By compounding the humidity-sensitive color-changing material with the conductive agent, the humidity-sensitive color-changing composition is endowed with certain electrical conductivity. When the humidity-sensitive color-changing composition is mixed with a base paste and applied in a photovoltaic module, the influence on the electrical conductivity and reliability of the cell paste can be minimized, the electrical conductivity of the grid line is more uniform, and when water vapor enters the interior of the photovoltaic module and corrodes the cell, the corrosion degree of the cell can be better determined by the color change of the grid line, the effect of the paste improvement can be determined, and the method is not affected by the adhesive film and glass material, is more intuitive, and responds faster than the traditional comparison of EL and electrical performance parameters. Specifically, when the humidity is greater than or equal to a predetermined value, the color developer in the humidity-sensitive color-changing material can provide protons or accept electrons to change the structure of the color-changing agent, thereby producing a color change. This color change phenomenon can be used to quantitatively evaluate the influence of the paste itself on the photovoltaic module caused by humidity, and by mixing the humidity-sensitive color-changing composition described above with the base paste to prepare a grid line, the effect of the paste improvement can be intuitively evaluated by observing the color of the grid line in a predetermined humidity environment. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0034] Figure 1 For some embodiments of the present application, a process flow diagram of a solar cell paste moisture resistance test method;

[0035] Figure 2 For some embodiments of the present application, a process flow diagram of a photovoltaic module fault monitoring method. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present application, the following will be a more comprehensive description of the present application in conjunction with the specific embodiments. The preferred embodiments of the present application are given in the specific embodiments. However, the present application can be realized in many different forms, and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0038] Unless otherwise stated or contradictory, the terms or phrases used in the present application have the following meanings:

[0039] In the present application, "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features.

[0040] In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0041] In the present application, "one or more" refers to any one, any two or any two or more of the listed items. Among them, "several" refers to any two or more.

[0042] In the present application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after adding the component.

[0043] The word "optionally" is used in this application to mean that some embodiments include the specified feature, while others do not. Consequently, use of "optionally" indicates that the described feature is an optional element or an element that is not required to be present. In addition, the use of "optionally", alone or in combination with another

[0044] When a range of values is disclosed, unless otherwise stated the endpoints of the ranges are not included. The endpoints are presumed to be the smallest and largest values so that the range of values is inclusive of the minimum and maximum. Further, these endpoints are provided to illustrate that the range of values is inclusive of the minimum and maximum values. In addition, there is a possibility that ranges of values within the disclosed small range of values are intended to be disclosed. Unless otherwise stated, the disclosure of any range of values should be interpreted as an explicit disclosure of each and every value and sub-range within the indicated range. The disclosure of a range of values can be used to describe a range of values that is inclusive of the minimum and maximum values, as well as intermediate values and sub-ranges within the range. Unless otherwise stated, the minimum and maximum values of the range are inclusive. The disclosure of a range of values can also be used to describe a range of values that excludes one or both of the minimum and maximum values, as well as intermediate values and sub-ranges within the range. Unless otherwise stated, the minimum value of the range is exclusive while the maximum value of the range is inclusive. In other words, unless otherwise stated, all ranges disclosed herein are to be interpreted as being inclusive of the minimum and maximum values, as well as intermediate values and sub-ranges within the range.

[0045] In the present application, the technical features described in an open-ended manner include both the closed technical solution consisting of the listed features and the open technical solution comprising the listed features.

[0046] The terms "comprises", "comprising", "includes", "including", "has", "having" and their conjugates as used herein, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of steps or elements is not necessarily limited to only those steps or elements but can include other not expressly listed steps or elements. In other words, the terms "comprises", "comprising", "includes", "including", "has", "having" and their conjugates are used herein to indicate that the process, method, article, or apparatus includes the listed steps or elements but not excluding other steps or elements.

[0047] Reference throughout this specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiment, or to a single alternative embodiment. It is appreciated that those skilled in the art will readily recognize that the application as described throughout this specification, embodiments thereof, and examples thereof, can be altered, modified, re-arranged, substituted, dissolved and / or combined in various ways without deviating from the spirit and scope of the application.

[0048] A first aspect of the present application provides a humidity-sensitive color-changing composition, comprising: a humidity-sensitive color-changing material and a conductive agent, the humidity-sensitive color-changing material comprising a color-changing agent and a color-developing agent in a mass ratio of (1-1.5):(100-105).

[0049] The color-developing agent is capable of providing protons or accepting electrons to cause the color-changing agent to change color when the humidity is greater than or equal to a preset value.

[0050] The humidity-sensitive color-changing composition of some embodiments of the present application comprises a humidity-sensitive color-changing material and a conductive agent. By compounding the humidity-sensitive color-changing material with the conductive agent, the humidity-sensitive color-changing composition is endowed with certain electrical conductivity, which does not affect the electrical conductivity and reliability when mixed with the base paste and applied in a photovoltaic module. When water vapor enters the interior of the photovoltaic module and corrodes the battery, the grid line color change can provide feedback to help better judge the corrosion degree of the battery and the effect of paste improvement. Compared with the traditional comparison of EL and component electrical performance parameters, the method is not affected by the adhesive film and glass material, and is more intuitive and fast. Specifically, when the humidity is greater than or equal to a preset value, the color-developing agent in the humidity-sensitive color-changing material can provide protons or accept electrons to change the structure of the color-changing agent, thereby producing a color change. This color-changing phenomenon can be used to quantitatively evaluate the humidity-affected photovoltaic module caused by the paste itself, and by mixing the above humidity-sensitive color-changing composition with the base paste to prepare a grid line, the color of the grid line in a preset humidity environment can be observed to intuitively evaluate the effect of paste improvement.

[0051] In addition, the above humidity-sensitive color-changing composition mixed with the battery paste for use in a photovoltaic module can also determine the degree and location of water vapor intrusion into the photovoltaic module in a timely and accurate manner according to the color information, thereby improving the analysis and judgment of the results of the damp-heat reliability.

[0052] A humidity-sensitive color-changing material is provided in the traditional technology, which uses a new type of rare earth ion to coordinate with an organic-inorganic conjugated material. The luminescence and opacity of the material can be dynamically adjusted under different humidity conditions. The main working principle is as follows: the fluorescence color adjustment is provided by the competitive effect between the non-conjugated chromophore and the dynamically coordinated rare earth ion (such as Eu 3+ ), and the change in opacity is caused by the phase separation / dissolution of the neutralized zwitterionic polymer in the dehydrated / hydrated state. However, the color change of this color-changing humidity-sensitive material has low distinguishability and high reliability risk, and is not suitable for use in battery paste. Specifically, rare earth metal elements have high chemical activity and can react with other materials in the element, causing changes in the structure of the element, corrosion or oxidation of the material, and affecting the performance and reliability of the element. Certain rare earth metal elements can promote the growth of crystal grains, leading to an increase in the size of the material crystal grains, thereby affecting the mechanical properties and stability of the material. In addition, the addition of rare earth metal elements can change the thermal stability of the material, causing changes in the performance of the material in high-temperature or low-temperature environments, thereby affecting the reliability of the element.

[0053] The wet-sensitive color-changing composition provided by some embodiments of the present application adopts an organic wet-sensitive color-changing material. When the ambient humidity reaches a preset value, the color-developing agent can provide protons or accept electrons to change the structure of the color-changing agent, thereby causing a color change. Under different humidity conditions, the color-changing agent can realize absorption of different visible light bands, thereby exhibiting different color changes, and the color change variability is high. Moreover, under the condition of humidity recovery, the color-changing agent can restore its initial color. In addition, compared with rare earth ion coordination organic-inorganic conjugated materials, the wet-sensitive color-changing composition of some embodiments of the present application has less impact on reliability.

[0054] In addition, the inventors found that under outdoor conditions, water vapor can enter the photovoltaic module from around the module and the glass holes, and then corrode the cell paste. If it cannot be found in time and maintained or replaced, it will cause the module to be mismatched, and ultimately cause a loss of power generation. However, in the conventional technology, the moisture corrosion condition of the photovoltaic module is often determined by sampling detection, and sampling testing has randomness and cannot be monitored comprehensively.

[0055] The wet-sensitive color-changing composition provided by some embodiments of the present application is mixed with the conventional paste and applied in the photovoltaic module. When the photovoltaic module is corroded by moisture, the color of the wet-sensitive color-changing composition can change, so that the color change of the appearance of the photovoltaic module can be obviously observed when personnel patrol, and the problem can be found, the reliability risk can be identified, and the photovoltaic module can be replaced, thereby avoiding the loss of power generation. Compared with the conventional sampling detection method, the photovoltaic module can be directly and comprehensively monitored, and a new method for monitoring the moisture influence on the photovoltaic module is provided.

[0056] In some embodiments, the color of the color-changing agent is different under different humidity conditions when the humidity is greater than or equal to a preset value. The color of the color-changing agent is different under different humidity conditions, which can further reflect the degree of corrosion of the grid line in the photovoltaic module by moisture.

[0057] In some embodiments, the color-changing agent includes an acid-base indicator. Specifically, the color-changing agent includes one or more of p-cresol red, thymol blue, litmus, phenothalin, thymolphthalein, phenol red, neutral red, malachite green, methyl red, methyl violet, methyl orange, methyl green, dimethyl yellow, bromothymol blue, bromophenol blue, dimethylphenol blue, methylene blue, azo red, azo yellow, azo orange, congo red, bromophenol red, bromomethyl green, bromomethyl violet, brilliant yellow, alizarin red S, and alizarin yellow R. Alternatively, the color-changing agent includes one or more of p-cresol red and thymol blue.

[0058] In some embodiments, the color-developing agent includes one or more of an acidic reagent and an alkaline reagent. Specifically, the color-developing agent includes one or more of boric acid, sulfuric acid, nitric acid, citric acid, acetic acid, sodium hydroxide, and potassium hydroxide. Alternatively, the color-developing agent includes boric acid.

[0059] The color-changing agent includes an acid-base indicator, and the color-developing agent includes one or more of an acidic reagent and a basic reagent. When the humidity is greater than or equal to a preset value, the acid-base concentration is different under different humidity conditions, the ionization degree of the color-changing agent is different, and thus different colors are displayed.

[0060] In one specific example, the mass ratio of the color-changing agent and the color-developing agent can be, but is not limited to, 1:100, 1:101, 1:102, 1:103, 1:104, 1:105, 1.2:100, 1.2:101, 1.2:102, 1.2:103, 1.2:104, 1.2:105, 1.5:100, 1.5:101, 1.5:102, 1.5:103, 1.5:104, 1.5:105, or a range formed by any two of these values.

[0061] In some embodiments, the humidity-sensitive color-changing material includes a color-changing agent and boric acid in a mass ratio of (1-1.5):(100-105), and the color-changing agent is selected from one or more of p-cresol red and thymol blue. Alternatively, the humidity-sensitive color-changing material includes a color-changing agent and boric acid in a mass ratio of 1:100, and the color-changing agent is selected from one or more of p-cresol red and thymol blue.

[0062] In some embodiments, the humidity-sensitive color-changing material further includes a hygroscopic agent. The addition of the hygroscopic agent to the humidity-sensitive color-changing material can achieve a more obvious color change, thereby improving the response capability of the humidity-sensitive color-changing composition to humidity changes.

[0063] In some embodiments, the hygroscopic agent includes one or more of silica gel, activated carbon, molecular sieve, bentonite, ethylene glycol, glycerol, xylitol, mannitol, and sorbitol. In one example, the hygroscopic agent includes silica gel.

[0064] In some embodiments, the mass ratio of the hygroscopic agent to the color-changing agent is (140-150):(1-1.5). For example, the mass ratio of the hygroscopic agent to the color-changing agent can be, but is not limited to, 140:1, 142:1, 145:1, 148:1, 150:1, 140:1.2, 142:1.2, 145:1.2, 148:1.2, 150:1.2, 140:1.5, 142:1.5, 145:1.5, 148:1.5, 150:1.5, or a range formed by any two of these values.

[0065] In some embodiments, the humidity-sensitive color-changing material includes a color-changing agent, boric acid, and silica gel in a mass ratio of (1-1.5):(100-105):(140-150), and the color-changing agent is selected from one or more of p-cresol red and thymol blue. Alternatively, the humidity-sensitive color-changing material includes a color-changing agent, boric acid, and silica gel in a mass ratio of 1:100:150.

[0066] The following takes p-cresol red as the color changing agent and boric acid as the color developing agent as an example to illustrate the color changing of the humidity-sensitive color changing material. It can be understood that the color changing principle of the color changing agent and the color developing agent can be referred to the following description, which will not be repeated here.

[0067] The color changing agent is p-cresol red and the color developing agent is boric acid. In a dry environment or when the humidity is low, the prepared humidity-sensitive color changing material is bright red. When the environmental humidity is greater than or equal to 60%, the color of the humidity-sensitive color changing material changes to yellow. The color changing is sharp and the color is bright, which is quite different from the color in the dry environment and is easy to observe. When the humidity continues to increase to 90%, the color of the humidity-sensitive color changing material changes to light yellow. When the humidity returns to the dry environment or when the humidity is low, the color of the humidity-sensitive color changing material changes back to bright red, which is a reversible humidity-sensitive color changing material. Therefore, when the above humidity-sensitive color changing material is applied in the solar cell paste, the condition of the grid lines affected by the humidity in the solar cell can be reflected in time according to the color change.

[0068] In some embodiments, the humidity-sensitive color changing material is obtained by grinding and mixing the color changing agent, the color developing agent and the hygroscopic agent.

[0069] In some embodiments, the conductive agent includes one or more of silver nanoparticles, gold nanoparticles and antimony tin oxide. It can be understood that the antimony tin oxide can be in the form of nanoparticles or powder. By mixing the humidity-sensitive color changing material with the conductive agent, the humidity-sensitive color changing material has a certain conductivity, so as to ensure that when it is applied to the solar cell paste subsequently, the influence on the conductivity and reliability of the cell paste can be minimized, and the conductivity of the grid lines is more uniform.

[0070] In some embodiments, the mass ratio of the humidity-sensitive color changing material to the conductive agent is 16:(3-8). For example, the mass ratio of the humidity-sensitive color changing material to the conductive agent can be, but is not limited to, 16:3, 16:3.5, 16:4, 16:4.5, 16:5, 16:5.5, 16:6, 16:6.5, 16:7, 16:7.5, 16:8 or a range formed by any two of these values. Alternatively, the mass ratio of the humidity-sensitive color changing material to the conductive agent is 16:(5-5.5).

[0071] In some embodiments, the humidity-sensitive color changing composition further includes a binder and / or a dispersant. The addition of the binder and the dispersant is beneficial to improve the mixing effect of the humidity-sensitive color changing material and the conductive agent, and at the same time, it is convenient for subsequent full mixing with the solar cell paste.

[0072] In some embodiments, the mass ratio of the moisture-sensitive color-changing material and the binder is 16:(1.5~3). For example, the mass ratio of the moisture-sensitive color-changing material and the binder can be, but is not limited to, 16:1.5, 16:1.6, 16:1.8, 16:2, 16:2.2, 16:2.4, 16:2.5, 16:2.6, 16:2.8, 16:3, or a range consisting of any two of these values.

[0073] In some embodiments, the mass ratio of the moisture-sensitive color-changing material and the dispersant is 16:(1~1.5). For example, the mass ratio of the moisture-sensitive color-changing material and the dispersant can be, but is not limited to, 16:1, 16:1.1, 16:1.2, 16:1.3, 16:1.4, 16:1.5, or a range consisting of any two of these values.

[0074] In some embodiments, the mass ratio of the moisture-sensitive color-changing material, the binder, the conductive agent, and the dispersant is 16:(1.5~3):(3~8):(1~1.5). Alternatively, the mass ratio of the moisture-sensitive color-changing material, the binder, the conductive agent, and the dispersant is 16:2:(5~5.5):1.

[0075] In some embodiments, the binder includes one or more of polyvinyl alcohol, sodium carboxymethyl cellulose, and sodium polyacrylate.

[0076] In some embodiments, the dispersant includes one or more of polyvinylpyrrolidone and sodium dodecyl sulfate.

[0077] In some embodiments, the moisture-sensitive color-changing composition includes the moisture-sensitive color-changing material, polyvinyl alcohol, silver nanoparticles, and polyvinylpyrrolidone in a mass ratio of 16:(1.5~3):(3~8):(1~1.5). Alternatively, the moisture-sensitive color-changing composition includes the moisture-sensitive color-changing material, polyvinyl alcohol, silver nanoparticles, and polyvinylpyrrolidone in a mass ratio of 16:2:(5~5.5):1.

[0078] In some embodiments, the moisture-sensitive color-changing composition is prepared by mixing the moisture-sensitive color-changing material, the binder, the conductive agent, and the dispersant.

[0079] The moisture-sensitive color-changing composition described above has conductivity and dispersibility, and can be fully mixed with conventional battery paste such as conductive silver paste, etc., to achieve minimal impact on the conductivity.

[0080] The second aspect of the present application provides a use of the moisture-sensitive color-changing composition in preparing solar cell paste.

[0081] The above moisture-sensitive color-changing composition can be mixed with a base paste to prepare a solar cell paste, which can intuitively feedback the moisture impact on the photovoltaic module caused by the paste itself through reversible color change, and better judge the improvement effect of the paste, while having little impact on the conductivity and reliability of the solar cell.

[0082] The third aspect of the present application provides a solar cell paste comprising the above moisture-sensitive color-changing composition and a base paste.

[0083] It can be understood that the base paste can be a paste commonly used in the art, such as conductive silver paste, and is not particularly limited herein.

[0084] The above solar cell paste, compared with the conventional paste, adds the moisture-sensitive color-changing composition, which can help analyze the source of the damp-heat attenuation of the photovoltaic module while ensuring the conductivity and reliability of the solar cell, and the corrosion damage caused by the damp-heat to the solar cell can be intuitively observed. On the other hand, the above solar cell paste is applied in the photovoltaic module, and through the color change of the grid line, it can also play a timely warning role in the outdoor power generation process, and the photovoltaic module corroded by moisture can be found in time to reduce the power generation loss.

[0085] In some embodiments, the mass ratio of the moisture-sensitive color-changing composition and the base paste is 1: (20-40). For example, the mass ratio of the moisture-sensitive color-changing composition and the base paste can be, but is not limited to, 1:20, 1:22, 1:25, 1:28, 1:30, 1:32, 1:35, 1:38, 1:40, or a range formed by any two of these values. By optimizing the mass ratio of the moisture-sensitive color-changing composition and the base paste, the impact on the conductivity and reliability of the prepared solar cell can be further reduced.

[0086] The fourth aspect of the present application provides a solar cell comprising a substrate and a grid line formed on the surface of the substrate, wherein the grid line is prepared by the above solar cell paste.

[0087] It can be understood that the solar cell also comprises conventional parts, which are not particularly limited herein and can be obtained according to conventional techniques in the art.

[0088] The fifth aspect of the present application provides a photovoltaic module comprising the above solar cell, an encapsulating adhesive film, and a cover plate, wherein the encapsulating adhesive film is arranged on the surface of the solar cell, and the cover plate is arranged on the surface of the encapsulating adhesive film away from the solar cell.

[0089] In some embodiments, the photovoltaic module comprises, in sequence, a glass, an encapsulating adhesive film, a solar cell, an encapsulating adhesive film, and a back plate. In other embodiments, the photovoltaic module comprises, in sequence, a glass, an encapsulating adhesive film, a solar cell, an encapsulating adhesive film, and a glass.

[0090] Referring to Figure 1 The sixth aspect of the present application provides a solar cell paste moisture resistance test method, comprising the following steps:

[0091] Step S110: using the above-mentioned solar cell paste to make the grid lines of the photovoltaic module;

[0092] Step S120: placing the photovoltaic module in a preset humidity environment, and judging the moisture resistance of the solar cell paste according to the color of the grid lines in the photovoltaic module.

[0093] Specifically, the solar cell paste is as described in the third aspect above, which will not be repeated here.

[0094] It can be understood that the preset humidity environment is greater than or equal to the humidity preset value at which the color change agent changes color.

[0095] The above-mentioned solar cell paste comprises a humidity-sensitive color-changing composition and a base paste. Without affecting the conductivity and reliability thereof, when water vapor enters the interior of the photovoltaic module and corrodes the battery, the color change of the grid lines can give feedback, helping to better judge the corrosion degree of the battery and the improvement effect of the paste. Compared with the traditional comparison of EL and component electrical performance parameters, the method is not affected by the adhesive film and glass material, and is more intuitive and fast in response. Specifically, the color change agent in the humidity-sensitive color-changing material presents different colors under the color developer and different humidity conditions. This color change phenomenon can be used to quantitatively evaluate the corrosion degree of the battery. By mixing the above-mentioned humidity-sensitive color-changing composition with the base paste to prepare the grid lines, the color of the grid lines can be observed to intuitively evaluate the improvement effect of the paste and the moisture resistance of the paste.

[0096] Figure 1 The flowchart of the solar cell paste moisture resistance test method of one embodiment of the present application is shown. It should be understood that although Figure 1 each step in the flowchart is displayed in sequence according to the arrow, these steps are not necessarily performed in the order indicated by the arrow, unless otherwise specified herein. The execution of these steps is not strictly limited in sequence, and they can be executed in other orders. Moreover, Figure 1 at least part of the steps in the flowchart can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times. The execution sequence is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or other sub-steps or stages.

[0097] Referring to Figure 2 The seventh aspect of the present application provides a photovoltaic module fault monitoring method, comprising the following steps:

[0098] Step S210: obtaining color information of the grid lines in the photovoltaic module, the photovoltaic module being as described above;

[0099] Step S220: monitoring the failure of the photovoltaic module according to the color information.

[0100] Specifically, the step S220 includes: if the color information of the grid lines is the color of the color changing agent when the humidity is less than the preset value, the photovoltaic module is less affected by the moisture corrosion, and the photovoltaic module works normally; if the color information of the grid lines is the color of the color changing agent when the humidity is greater than or equal to the preset value, the photovoltaic module is greatly affected by the moisture corrosion, and the photovoltaic module fails.

[0101] The grid lines in the photovoltaic module are prepared by mixing the moisture-sensitive color changing composition provided by some embodiments of the present application with the traditional paste. When the photovoltaic module is corroded by moisture, the color of the grid lines can change, so that the color change of the appearance can be obviously observed when the personnel patrol, the reliability risk can be identified, the failure can be investigated, and the module can be replaced, thereby avoiding the loss of power generation. Compared with the traditional sampling detection method, the method can intuitively and comprehensively monitor the moisture-affected condition of the photovoltaic module, and provides a new method for monitoring the moisture-affected condition of the photovoltaic module.

[0102] In order to make the purpose and advantages of the present application more clear, the moisture-sensitive color changing composition and its effects of the present application will be further described in detail in combination with specific examples. It should be understood that the specific examples described herein are only used to explain the present application and should not be used to limit the present application. The following examples do not include other components except for unavoidable impurities unless otherwise specified. In the examples, the drugs and instruments are selected according to the conventional selection in the art unless otherwise specified. The experimental methods not specified in the examples are carried out according to the conventional conditions, such as the conditions described in the literature, books or the methods recommended by the manufacturer.

[0103] Example 1

[0104] The present embodiment provides a solar cell paste, which comprises a base paste and a moisture-sensitive color changing composition in a mass ratio of 25:1, wherein the base paste is a silver paste. The moisture-sensitive color changing composition comprises a moisture-sensitive color changing material, a polyvinyl alcohol binder, a nano-silver particle and a polyvinylpyrrolidone dispersant in a mass ratio of 16:2:5:1. The moisture-sensitive color changing material comprises p-cresol red, boric acid and silica gel in a mass ratio of 1:100:150.

[0105] Comparative Example 1

[0106] Comparative Example 1 provides a solar cell paste, which only comprises a base paste. The base paste of Comparative Example 1 is the same as that of Example 1.

[0107] The following is a specific test part:

[0108] 1. The performance of the solar cell paste of Example 1 and Comparative Example 1 was tested, using 210-HJT cells, printing under the same screen, and testing the height, width, pad point height, and line resistance of the grid lines of 15 solar cells simultaneously, with the results shown in Table 1. Among them, the pad point is a plurality of local points on the main grid line, which are evenly distributed on the main grid line as a wiring point, and are located at the intersection of the fine grid line and the main grid line, and are used for the contact and fixation of the solder strip and the cell piece.

[0109] Table 1 Performance comparison of solar cell paste of examples and comparative examples

[0110]

[0111] From the above results, it can be seen that the line resistance of the grid line prepared using the solar cell paste of Example 1 is slightly decreased, but the overall efficiency of the cell differs by 0.08% or less from the original efficiency.

[0112] 2. The solar cell paste of Example 1 and Comparative Example was printed on a silicon wafer treated by conventional processes such as texturing, and the two were assembled into photovoltaic modules, respectively, and placed in different humidity environments, i.e. humidity 30%, humidity 60%, and humidity 90%, to compare the solar cell paste of the comparative example and the comparative example to see if different humidity can present the color in the ideal state. The results are shown in Table 2.

[0113] Table 2 Test results of examples and comparative examples in different humidity environments

[0114]

[0115] It should be noted that in Table 2, during the power decay test after 1000h, two samples were tested under each experimental condition, for example, the power decay of the solar cell of Comparative Example 1 was 0.78% / 0.51% after 1000h under the condition of RH: 30%, T=25℃, which means that the power decay of the two samples was 0.78% and 0.51%, respectively.

[0116] From the above Table 2, it can be seen that the solar cell paste of the example, by adding the humidity-sensitive color-changing composition, the grid lines of the photovoltaic module prepared can present different color changes under different humidity environments, directly reflecting the degree of influence of the cell on the heat and humidity. And compared with the conventional paste without adding the humidity-sensitive color-changing composition, the power decay of the photovoltaic module changes little, and the power decay after 1000h is less than 5%, meeting the industry standard requirements of IEC, i.e. the reliability of the cell is not greatly affected.

[0117] Any technical features in the above-described embodiments can be combined, and for the sake of brevity, not all possible combinations of the technical features are described, however, any combination of the technical features should be considered as within the scope of the present disclosure.

[0118] The above-described embodiments only express several implementation manners of the present application, facilitate specific and detailed understanding of the technical solutions of the present application, but should not be understood as a limitation on the patent protection scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, a number of modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. It should be understood that, on the basis of the technical solutions provided by the present application, technical solutions obtained by logical analysis, reasoning or limited experiments by those skilled in the art all belong to the protection scope of the appended claims of the present application. Therefore, the patent protection scope of the present application should be subject to the contents of the appended claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A moisture-sensitive color-changing composition, characterized in that, It includes a moisture-sensitive color-changing material and a conductive agent, wherein the moisture-sensitive color-changing material comprises a color-changing agent and a color-developing agent in a mass ratio of (1~1.5):(100~105); Specifically, when the humidity is greater than or equal to a preset value, the color-developing agent can provide protons or accept electrons to change the color of the color-changing agent.

2. The moisture-sensitive color-changing composition according to claim 1, characterized in that, One or more of the following conditions must be met: (1) The color-changing agent includes an acid-base indicator; Optionally, the color-changing agent includes one or more of the following: p-cresol red, thymol blue, litmus, phenolphthalein, thymolphthalein, phenol red, neutral red, malachite green, methyl red, methyl violet, methyl orange, methyl green, dimethyl yellow, bromothymol blue, bromophenol blue, xylenol blue, methylene blue, azo red, azo yellow, azo orange, Congo red, bromophenol red, bromocresol green, bromocresol violet, daldan yellow, alizarin red S, and alizarin yellow R. Optionally, the color-changing agent includes one or more of p-cresol red and thymol blue; (2) The colorimetric reagent includes one or more of acidic and alkaline reagents; Optionally, the colorimetric agent includes one or more of boric acid, sulfuric acid, nitric acid, citric acid, acetic acid, sodium hydroxide, and potassium hydroxide.

3. The moisture-sensitive color-changing composition according to claim 1, characterized in that, The moisture-sensitive color-changing material also includes a hygroscopic agent, and the mass ratio of the hygroscopic agent to the color-changing agent is (140~150):(1~1.5). Optionally, the desiccant includes one or more of silica gel, activated carbon, molecular sieve, bentonite, ethylene glycol, glycerol, xylitol, mannitol, and sorbitol.

4. The moisture-sensitive color-changing composition according to claim 1, characterized in that, The mass ratio of the moisture-sensitive color-changing material to the conductive agent is 16:(3~8). Optionally, the mass ratio of the moisture-sensitive color-changing material to the conductive agent is 16:(5~5.5). Optionally, the conductive agent includes one or more of silver nanoparticles, gold nanoparticles, and antimony-tin oxide.

5. The moisture-sensitive color-changing composition according to any one of claims 1 to 4, characterized in that, The moisture-sensitive color-changing composition further includes an adhesive, wherein the mass ratio of the adhesive to the moisture-sensitive color-changing material is (1.5~3):16; Optionally, the adhesive comprises one or more of polyvinyl alcohol, sodium carboxymethyl cellulose, and sodium polyacrylate.

6. The moisture-sensitive color-changing composition according to any one of claims 1 to 4, characterized in that, The moisture-sensitive color-changing composition further includes a dispersant, wherein the mass ratio of the dispersant to the moisture-sensitive color-changing material is (1~1.5):16; Optionally, the dispersant includes one or more of polyvinylpyrrolidone and sodium dodecyl sulfate.

7. The use of the moisture-sensitive color-changing composition according to any one of claims 1 to 6 in the preparation of solar cell paste.

8. A solar cell paste, characterized in that, Includes the moisture-sensitive color-changing composition and base slurry as described in any one of claims 1 to 6.

9. The solar cell paste according to claim 8, characterized in that, The mass ratio of the moisture-sensitive color-changing composition to the base slurry is 1:(20~40).

10. A solar cell, characterized in that, It includes a substrate and grid lines formed on the surface of the substrate, the grid lines being prepared using the solar cell paste according to any one of claims 8 to 9.

11. A photovoltaic module, characterized in that, The invention includes the solar cell, encapsulating film, and cover plate as described in claim 10, wherein the encapsulating film is disposed on the surface of the solar cell, and the cover plate is disposed on the side of the encapsulating film away from the solar cell.

12. A method for testing the moisture resistance of solar cell paste, characterized in that, Includes the following steps: The grid lines of a photovoltaic module are made using the solar cell paste according to any one of claims 8 to 9; The photovoltaic module is placed in a preset humidity environment, and the moisture resistance of the solar cell paste is determined based on the color of the grid lines in the photovoltaic module.

13. A method for monitoring faults in photovoltaic modules, characterized in that, Includes the following steps: Obtain the color information of the grid lines in the photovoltaic module, the photovoltaic module as described in claim 11; The fault status of the photovoltaic module is monitored based on the color information.

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