Laminated battery packaging adhesive film, preparation method thereof and laminated battery assembly

Abstract

The invention discloses a laminated cell packaging adhesive film, a preparation method thereof and a laminated cell module, and belongs to the technical field of photovoltaic cells. The packaging adhesive film comprises a first bonding layer; the first bonding layer at least meets one of the following conditions: (1) the mass percent of volatile substances of the first bonding layer at the temperature of 105 DEG C is less than 0.5%; and (2) the mass percent of substances dissolved in ethanol in the first bonding layer is less than 1.0%. The adhesive film has good stability, barrier property and insulativity, can reduce the creep deformation problem generated by a crystalline silicon cell, and improves the efficiency of a laminated cell.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic cells, and in particular to a laminated cell packaging film and a preparation method thereof, and a laminated cell assembly. Background Art

[0002] Today, with energy shortages and environmental issues becoming increasingly prominent, it has become an inevitable trend to find renewable, environmentally friendly green energy. Photovoltaic power generation is the process of converting solar energy into electrical energy. It has three advantages: permanence, cleanliness, and flexibility. Compared with traditional thermal power generation, hydropower generation, and nuclear power generation, its preparation process is simple and highly reproducible, so it has a good development prospect.

[0003] In recent years, photovoltaic cell technology has developed rapidly. In the field of crystalline silicon, the conversion efficiency of new high-efficiency cells such as HJT and Topcon has reached more than 26%, which is getting closer and closer to the theoretical limit of crystalline silicon cells, and it is becoming more and more difficult to improve efficiency. With the maturity of thin-film battery (cadmium telluride, perovskite, etc.) battery technology, the stacked components of thin-film batteries + crystalline silicon batteries can make fuller use of sunlight by taking advantage of the different bandwidths of the two batteries, and the theoretical conversion limit is as high as more than 40%. At present, the conversion efficiency of perovskite + crystalline silicon stacked components has exceeded 30%, becoming an important development direction for the next generation of high-efficiency components.

[0004] In the above-mentioned stacked battery structure, there is an encapsulation film between the thin-film battery and the crystalline silicon battery, which is used to isolate the migration of small molecules or ions between the two batteries; the conventional encapsulation film can protect and isolate the two batteries at the same time due to its material characteristics or structural design, but the effect is poor; it cannot specifically solve the creep problems caused by the crystalline silicon battery and the isolation and insulation effects are poor, as well as the problems that affect the battery stability and battery efficiency; therefore, it is necessary to develop new encapsulation films specifically according to the different structural characteristics of this stacked battery. Summary of the invention

[0005] The main purpose of the present application is to provide a laminated battery packaging film and a preparation method thereof and a laminated battery assembly, so as to solve the problem in the prior art that the packaging film cannot effectively isolate and protect the laminated battery and thus affects the battery stability and battery efficiency.

[0006] In order to achieve the above object, according to one aspect of the present application, a laminated battery packaging film is provided, the packaging film includes a first adhesive layer; the first adhesive layer at least meets one of the following conditions:

[0007] (1) The mass percentage of volatile matter in the first adhesive layer at a temperature of 105° C. is less than 0.5%;

[0008] (2) The mass percentage of the substance soluble in ethanol in the first adhesive layer is less than 1.0%.

[0009] Furthermore, the raw materials of the first bonding layer include: 0% to 60% of the first base resin and 40% to 100% of the modified resin.

[0010] Furthermore, the mass percentage of the first base resin is 5% to 60%, and the mass percentage of the modified resin is 40% to 95%.

[0011] Furthermore, the mass percentage of the first base resin is 10% to 60%, and the mass percentage of the modified resin is 40% to 90%.

[0012] Further, the first base resin is selected from at least one of ethylene-vinyl acetate copolymer, polyolefin elastomer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer and polymethyl methacrylate.

[0013] Further, the polyolefin elastomer in the first base resin is at least one selected from ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer.

[0014] Furthermore, the modified resin is a silane-modified ethylene-vinyl acetate copolymer and / or a silane-modified polyolefin elastomer.

[0015] Further, the silane-modified polyolefin elastomer is at least one selected from a silane-modified ethylene-octene copolymer, a silane-modified ethylene-hexene copolymer and a silane-modified ethylene-butene copolymer.

[0016] Furthermore, the first adhesive layer has an exothermic enthalpy of less than 1.0 J / g in a temperature range of 130° C. to 190° C.

[0017] Furthermore, the melting point of the first adhesive layer is 70° C. to 120° C., and the melting index is ≤10 g / 10 min.

[0018] Furthermore, the thickness of the first adhesive layer is 0.2-0.5 mm.

[0019] Furthermore, the light transmittance of the first adhesive layer is greater than or equal to 85%.

[0020] Furthermore, the packaging film further includes a second adhesive layer stacked with the first adhesive layer.

[0021] Furthermore, in terms of mass percentage, the raw materials of the second adhesive layer include: 95% to 99.65% of the second base resin, 0.1% to 2% of an initiator, 0.2% to 2% of a co-crosslinking agent, and 0.05% to 1% of a tackifier.

[0022] Further, the second base resin is ethylene-vinyl acetate copolymer and / or polyolefin elastomer.

[0023] Further, the polyolefin elastomer in the second base resin is at least one selected from ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer.

[0024] Furthermore, the thickness of the second adhesive layer is 0.2 to 0.6 mm, preferably 0.3 to 0.5 mm.

[0025] Furthermore, the light transmittance of the second adhesive layer is greater than or equal to 90%.

[0026] Furthermore, a barrier layer is disposed between the first adhesive layer and the second adhesive layer.

[0027] Furthermore, the material of the barrier layer is selected from at least one of polyethylene terephthalate, polypropylene, polyethylene, polyamide, polycarbonate and polymethyl methacrylate.

[0028] Furthermore, the thickness of the barrier layer is 0.025 to 0.2 mm, and more preferably 0.05 to 0.2 mm.

[0029] Furthermore, the breakdown voltage of the barrier layer is greater than or equal to 25 kV / mm.

[0030] Furthermore, the light transmittance of the barrier layer is greater than or equal to 85%.

[0031] Furthermore, the raw materials of the first bonding layer and / or the second bonding layer also include a photoconversion agent.

[0032] Furthermore, the proportion of the photoconversion agent in the total mass of the raw materials of the first bonding layer is 0-2.0%; furthermore, 0.5%-1.5%.

[0033] Furthermore, the proportion of the photoconversion agent in the total mass of the raw materials of the second bonding layer is 0-2.0%; furthermore, 0.5%-1.5%.

[0034] Furthermore, the light conversion agent is selected from light conversion agents having the function of converting infrared light into visible light.

[0035] Furthermore, the photoconverter is selected from an inorganic matrix doped with rare earth ions.

[0036] Furthermore, the rare earth ion doping method is selected from single doping, double doping or multi-doping.

[0037] Furthermore, the rare earth ion is selected from Er 3+ 、Ho 3+ 、Tm 3+ and Yb 3+ At least one of .

[0038] Furthermore, the inorganic matrix is ​​selected from at least one of fluorides, oxides, sulfur-containing compounds, oxyfluorides and halides.

[0039] Further, the fluoride is selected from LiYF 4 ,NaYF 4 ,NaGdF 4 ,BaY 2 F 8 and CaF 2 At least one of .

[0040] Further, the oxide is selected from Gd 2 O 3 , Y 2 O 3 、CeO 2 , Er 2 O 3 and YVO 4 At least one of .

[0041] Furthermore, the sulfur-containing compound is selected from La 2 S 3 and / or CaS.

[0042] Further, the oxyfluoride is selected from GdOF and / or YOF.

[0043] Further, the halide is selected from ZnCl 2 , CdCl 2 and Cs 3 Lu 2 Br 9 At least one of .

[0044] Furthermore, the photoconverter is selected from NaYF 4 -Yb 3+ 、GdOF-Yb 3+ / Er 3+ 、BaTiO 3 -Yb 3+ / Er 3+ 、BaTiO 3 -Yb 3 + / Tm 3+ ,La 2 O 3 -Yb 3+ / Er 3+ , Y 2 O 3 -Yb 3+ / Er 3+ , Er 3+ Rare earth upconversion luminescent nanoparticles, KZnF 3 -Er3+ 、Tm 3+ , Yb 3+ Rare earth upconversion luminescent nanoparticles, YLiF 4 -Er 3+ ,NaYF 4 -Er 3+ / Yb 3+ ,LiYF 4 -Yb 3+ / Er 3+ 、NaYF4-Yb 3+ / Tm 3+ ,NaYF 4 -Ho 3+ / Yb 3+ 、Ho 3+ / Yb 3+ Co-doped Gd 2 O 3 and E 3+ / Yb 3+ Co-doped CeO 2 At least one of the conversion materials on the nanowire.

[0045] Further, the initiator is selected from peroxides.

[0046] Further, the peroxide is selected from at least one of butyl peroxycarbonate isopropyl, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate and peroxy-3,3,5-trimethyltert-butyl hexanoate.

[0047] Further, the auxiliary crosslinking agent is selected from triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ditrimethylolpropane At least one of tetraacrylate, ditrimethylolpropane tetramethacrylate, propoxylated pentaerythritol tetraacrylate, 2,4,6-tris(2-propenyloxy)-1,3,5-triazine, tricyclopentane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and polyethylene glycol dimethacrylate.

[0048] Furthermore, the tackifier is selected from at least one of silane coupling agents, silane-modified ethylene-vinyl acetate copolymers, silane-modified polyolefin elastomers, silane-modified ethylene-methyl acrylate copolymers, silane-modified ethylene-acrylic acid copolymers and silane-modified polymethyl methacrylate.

[0049] Further, the silane coupling agent is selected from at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-aminopropyl triethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ-glycidyloxypropyl trimethylsilane and 3-aminopropyl trimethylsilane.

[0050] According to the second aspect of the present application, a method for preparing the above-mentioned encapsulation film is provided, including a melt extrusion method, a one-step molding method or a lamination and two-time lamination method:

[0051] The melt extrusion method comprises: melting and mixing the raw materials, extruding and molding, and obtaining a packaging film with a layer structure;

[0052] The one-step molding method is to use a cast double-layer co-extrusion method to form the film in one step, so that the two layers of film materials are stacked on each other to obtain a two-layer packaging film;

[0053] The double lamination method includes: firstly, one layer of film material is prepared by cast extrusion, and then another layer of molten raw material is poured on the surface of the first prepared film material by lamination lamination, and finally the two layers of film material are rolled to make the two layers of film material fit closely to obtain a two-layer packaging film.

[0054] According to a third aspect of the present application, a laminated battery assembly is provided, comprising a laminated battery and a packaging film; wherein the packaging film is the above-mentioned laminated battery packaging film or the packaging film prepared by the above-mentioned preparation method.

[0055] Furthermore, the two types of batteries are thin film batteries and crystalline silicon batteries.

[0056] Furthermore, the thin film battery is selected from at least one of a perovskite battery, a cadmium telluride battery and a copper indium gallium selenide battery.

[0057] Furthermore, the stacked cells in the stacked cell assembly are perovskite cells-crystalline silicon cells.

[0058] Furthermore, the laminated battery assembly includes a front plate, a thin film battery, a front layer packaging film, a crystalline silicon battery, a rear layer packaging film and a rear plate in sequence; wherein the front layer packaging film is the above-mentioned laminated battery packaging film or the packaging film prepared by the above-mentioned preparation method.

[0059] Furthermore, the first adhesive layer of the packaging film is laminated with the adjacent thin-film battery.

[0060] Furthermore, the laminated assembly comprises a front plate, a first packaging film, a thin film battery-crystalline silicon battery, a second packaging film and a back plate; wherein the first packaging film is the above-mentioned laminated battery packaging film or the packaging film prepared by the above-mentioned preparation method.

[0061] By applying the technical solution of the present application, a laminated battery packaging film, a preparation method thereof and a laminated battery assembly are provided; the packaging film is arranged in the laminated battery, and the mass percentage of volatile substances in the first adhesive layer material under the temperature of 105°C is less than 0.5% and the mass percentage of substances soluble in ethanol is less than 1.0%, the components are stable, and the reactive auxiliary agent is small, so that the stability of the thin film battery can be ensured; at the same time, the adhesive layer material also has good barrier properties and insulating properties, which can avoid the problem of reduced battery efficiency due to the migration of small molecules and ions between laminated batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0063] Figure 1 A schematic diagram of the structure of a laminated battery assembly in Example 1 of the present application is shown;

[0064] Figure 2 A schematic diagram of the creep resistance test of the laminated battery packaging film of the present application is shown.

[0065] Reference numerals:

[0066] 1. Front plate; 2. Thin film battery; 3. Front encapsulation film; 4. Crystalline silicon battery; 5. Back encapsulation film; 6. Back plate; 4', hook; 5', structural adhesive; 6', first glass; 7', encapsulation film; 8', second glass. DETAILED DESCRIPTION

[0067] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0068] There is an encapsulation film between the two batteries in the stacked battery structure, such as the encapsulation film between the thin-film battery and the crystalline silicon battery, which is used to isolate the migration of small molecules or ions between the two batteries. Conventional encapsulation films mainly play a role of protecting and isolating the two batteries at the same time due to their material characteristics or structural combination characteristics. However, the two batteries have different structural characteristics and material characteristics, and the encapsulation film has no targeted effect between the two batteries. The overall effect is poor, and it is even more unable to specifically solve the creep problems caused by the crystalline silicon battery and the isolation and insulation effects are poor, as well as the problems affecting battery stability and battery efficiency.

[0069] According to one aspect of the present application, a laminated battery packaging film is provided, comprising a first adhesive layer; the first adhesive layer satisfies at least one of the following conditions:

[0070] (1) The mass percentage of volatile matter in the first adhesive layer at a temperature of 105° C. is less than 0.5%;

[0071] (2) The mass percentage of the substance soluble in ethanol in the first adhesive layer is less than 1.0%.

[0072] The above-mentioned laminated battery encapsulation film provided in the present application is arranged in the laminated battery, and its first adhesive layer material has the advantages that the mass percentage of volatile substances at a temperature of 105°C is less than 0.5% and the mass percentage of substances soluble in ethanol is less than 1.0%. It has low volatility, low solubility, and stable material components, which can further ensure the stability of the thin film battery; at the same time, the first adhesive layer material has good barrier properties and insulation properties, which can avoid the problem of reduced battery efficiency due to the migration of small molecules and ions between laminated batteries.

[0073] In some embodiments, the raw materials of the first bonding layer include, by mass percentage, 0% to 60% of the first base resin and 40% to 100% of the modified resin. For example, the mass percentage of the first base resin of the raw materials of the first bonding layer is selected from any value of 0%, 2%, 3%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60% or any range between two values; the mass percentage of the modified resin is selected from any value of 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100% or any range between two values. Further, the first base resin is 5% to 60%, and the modified resin is 40% to 95%; further, the first base resin is 10% to 60%, and the modified resin is 40% to 90%; more specifically, the first base resin is 20% to 60%, and the modified resin is 40% to 80%. The above-mentioned component ratios used in this application can further improve the stability, barrier and insulation of the first adhesive layer material, avoid the problem of reduced battery efficiency caused by the migration of small molecules and ions between stacked batteries, and are beneficial to the stability of thin-film batteries.

[0074] In some embodiments, the first base resin is selected from at least one of ethylene-vinyl acetate copolymer, polyolefin elastomer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer and polymethyl methacrylate. Further, the polyolefin elastomer is selected from at least one of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer. The first base resin material selected in the present application is stable, has good light transmittance, barrier properties and insulation, and can improve the power generation efficiency of crystalline silicon cells.

[0075] In some embodiments, the silane-modified resin is prepared by free radical grafting reaction of a base resin, an initiator and a silane coupling agent; the initiator and the silane coupling agent can be selected from the prior art; wherein the mass ratio of the base resin, the initiator and the silane coupling agent is (100):(0.1-0.5):(0.5-3); further, the modified resin is a silane-modified ethylene-vinyl acetate copolymer and / or a silane-modified polyolefin elastomer; further, the silane-modified polyolefin elastomer is selected from at least one of a silane-modified ethylene-octene copolymer, a silane-modified ethylene-hexene copolymer and a silane-modified ethylene-butene copolymer. The above-mentioned modified resin component selected in the present application is stable and can ensure the stability of the thin film battery.

[0076] In some embodiments, the thickness of the first adhesive layer is 0.2 to 0.5 mm, for example, 0.2 to 0.4 mm, and the transmittance is greater than or equal to 85%; the exothermic enthalpy of the first adhesive layer within the temperature range of 130°C to 190°C is less than 0.1 J / g; the melting point is 70°C to 120°C; and the melt index is ≤10g / 10min. The present application is more conducive to the photoelectric conversion of thin-film batteries and crystalline silicon batteries by limiting the thickness and transmittance of the first adhesive layer; the material of the first adhesive layer of the present application is a thermoplastic material, without small molecule additives, with good heat resistance, stable chemical properties, good insulation and barrier properties, and can prevent the cross-linking layer additives from migrating to the surface of the thin-film battery and thus destroying the battery stability.

[0077] In some embodiments, the packaging film further includes a second adhesive layer, the raw materials of which include 95% to 99.65% of a second base resin, 0.1% to 2% of an initiator, 0.2% to 2% of a co-crosslinking agent, and 0.05% to 1% of a tackifier. For example, the mass percentage of the second base resin of the second bonding layer raw material is selected from any value among 95%, 96%, 97%, 98%, 99%, 99.5%, 99.65%, or any range between two of them; the mass percentage of the initiator is selected from any value among 0.1%, 0.5%, 1.0%, 1.5%, 2%, or any range between two of them; the mass percentage of the auxiliary cross-linking agent is selected from any value among 0.2%, 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 1.8%, 2%, or any range between two of them; the mass percentage of the tackifier is selected from any value among 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or any range between two of them. More specifically, the raw materials of the second adhesive layer include: 96% to 99% of the second base resin, 0.3% to 1.5% of the initiator, 0.6% to 1.5% of the cross-linking agent, and 0.1% to 1% of the tackifier. The above-mentioned composition ratios used in this application can further improve the barrier properties, insulation properties, and cross-linking degree of the second adhesive layer material, and can better solve the problems of creep caused by the increase in component temperature due to the heat generated by the crystalline silicon battery during operation, and avoid the problem of reduced battery efficiency due to the migration of small molecules and ions between stacked batteries.

[0078] The encapsulation film of the present application is arranged between the thin-film battery and the crystalline silicon battery. The first adhesive layer material component is stable and has less reactive additives, which can ensure the stability of the thin-film battery; the second adhesive layer raw material is added with a cross-linking agent, which synergizes with other components to further promote the cross-linking reaction of the raw material molecules and improve the performance of the second adhesive layer material; the second adhesive layer material has a high degree of cross-linking, which meets the reliability of the stacked battery assembly and can reduce a series of problems such as creep caused by the heat generated by the crystalline silicon battery during operation and the temperature rise of the assembly; at the same time, the two adhesive layer materials also have good barrier properties and insulation properties, which can avoid the problem of reduced battery efficiency due to the migration of small molecules and ions between the thin-film battery and the crystalline silicon battery.

[0079] In some embodiments, the second base resin is ethylene-vinyl acetate copolymer and / or polyolefin elastomer; further, the polyolefin elastomer is selected from at least one of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer. The second bonding layer material obtained by the synergistic effect of the second base resin selected in the present application and other components has a high degree of crosslinking, meets the reliability of the laminated battery assembly, and can reduce the creep caused by the increase in assembly temperature due to the heat generated by the crystalline silicon battery during operation.

[0080] In some embodiments, the thickness of the second adhesive layer is 0.2 to 0.6 mm, for example, 0.3 to 0.5 mm; the light transmittance is greater than or equal to 85%, and further greater than 90%. By limiting the thickness and light transmittance of the second adhesive layer, the present application is more conducive to thin-film batteries and crystalline silicon batteries absorbing light, and the adhesive layer also has good insulation and barrier properties.

[0081] In some embodiments, a barrier layer is further disposed between the first adhesive layer and the second adhesive layer. In the present application, an intermediate barrier layer is disposed between the two adhesive layers of the packaging film. Since the barrier layer has good insulation and barrier properties, the insulation problem caused by the potential difference between the two layers of batteries can be avoided, and the migration of small molecule additives and ions between the battery layers can be further prevented.

[0082] In some embodiments, the material of the barrier layer is selected from at least one of polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polycarbonate (PC), polycarbonate and polymethyl methacrylate (PMMA). The barrier material selected in the present application has good electrical insulation performance, heat resistance, chemical stability, impact resistance and good transparency, can meet the insulation and transparency requirements, and has a good composite effect with the first adhesive layer and the second adhesive layer, and will not affect the material characteristics and structure of the adhesive layers on both sides.

[0083] In some embodiments, the thickness of the barrier layer is 0.025 to 0.2 mm; for example, 0.05 to 0.2 mm, further 0.1 to 0.2 mm; the breakdown voltage of the barrier layer is greater than or equal to 25 kV / mm; the light transmittance of the barrier layer is greater than or equal to 85%. The present application selects a barrier layer material with the above-mentioned specific thickness, electrical strength value, and light transmittance, which can further achieve better insulation and light transmission performance of the barrier layer, so as to facilitate the photoelectric conversion efficiency of thin-film batteries and crystalline silicon batteries.

[0084] In some embodiments, the raw materials of the first bonding layer and / or the second bonding layer also include a photoconverter; when the first bonding layer contains a photoconverter, the photoconverter accounts for 0 to 2.0% of the total mass of the raw materials of the first bonding layer; for example, 0.5% to 1.5%; when the second bonding layer contains a photoconverter, the photoconverter accounts for 0 to 2.0% of the total mass of the raw materials of the second bonding layer; for example, 0.5% to 1.5%. In the present application, adding a photoconverter to the bonding layer material can convert infrared into visible light, which can improve the absorption conversion rate of thin-film batteries (perovskite batteries) to infrared or near-infrared and the power generation efficiency of crystalline silicon batteries.

[0085] In some embodiments, the photoconversion agent is selected from a photoconversion agent having the function of converting infrared light into visible light; for example, the photoconversion agent is selected from an inorganic matrix doped with rare earth ions; wherein the doping method of the rare earth ions is selected from single doping, double doping or multi-doping; the rare earth ions are selected from Er 3+ 、Ho 3+ 、Tm 3+ and Yb 3+ At least one of the following: the inorganic matrix is ​​selected from at least one of fluorides, oxides, sulfur-containing compounds, oxyfluorides and halides; the fluoride is selected from LiYF 4 ,NaYF 4 ,NaGdF 4 ,BaY 2 F 8 and CaF 2 At least one of; oxide selected from Gd 2 O 3 , Y 2 O 3 、CeO 2 , Er 2 O 3 and YVO 4 At least one of; sulfur-containing compounds selected from La 2 S 3 and / or CaS; the oxyfluoride is selected from GdOF and / or YOF; the halide is selected from ZnCl 2 , CdCl 2 or Cs 3 Lu 2 Br9 More specifically, the photoconverter is selected from NaYF 4 -Yb 3+ 、GdOF-Yb 3+ / Er 3+ 、BaTiO 3 -Yb 3+ / Er 3+ 、BaTiO 3 -Yb 3+ / Tm 3+ ,La 2 O 3 -Yb 3+ / Er 3+ , Y 2 O 3 -Yb 3+ / Er 3+ , Er 3+ Rare earth upconversion luminescent nanoparticles, KZnF 3 -Er 3+ 、Tm 3+ , Yb 3+ Rare earth upconversion luminescent nanoparticles, YLiF 4 -Er 3+ ,NaYF 4 -Er 3+ / Yb 3+ ,LiYF 4 -Yb 3+ / Er 3+ 、NaYF4-Yb 3+ / Tm 3+ ,NaYF 4 -Ho 3+ / Yb 3+ 、Ho 3+ / Yb 3+ Co-doped Gd 2 O 3 and E 3+ / Yb 3+ Co-doped CeO 2 At least one of the conversion materials on the nanowire.

[0086] The up-conversion material of the above-mentioned substance selected in the present application is a special type of luminescent material, in which rare earth elements are used as activation ions. These ions can realize up-conversion luminescence through multi-photon absorption and energy transfer processes, and they can convert low-energy photons (such as near-infrared light) into high-energy photons (such as visible light); the up-conversion material is an up-conversion photochromic material, which can produce photochromic changes to light with a wavelength of 980 to 1600nm, so as to effectively convert light of 980 to 1600nm into visible light.

[0087] In some embodiments, the initiator is selected from peroxides; further, the peroxide is selected from at least one of butyl peroxycarbonate isopropyl, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate and peroxy-3,3,5-trimethylt-butyl hexanoate.

[0088] In some embodiments, the auxiliary crosslinking agent is selected from triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ditrimethylolpropane ... trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated tri At least one of propane tetraacrylate, ditrimethylolpropane tetramethacrylate, propoxylated pentaerythritol tetraacrylate, 2,4,6-tris(2-propenyloxy)-1,3,5-triazine, tricyclopentane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate and polyethylene glycol dimethacrylate.

[0089] The above-mentioned auxiliary cross-linking agent and other components selected in the present application work synergistically to further promote the cross-linking reaction of the raw material molecules, so that the second adhesive layer material has a higher degree of cross-linking, which meets the reliability of the laminated battery assembly and can reduce a series of problems such as creep caused by the heat generated by the operation of the crystalline silicon battery and the increase in the temperature of the assembly.

[0090] In some embodiments, the tackifier is selected from at least one of a silane coupling agent, a silane-modified ethylene-vinyl acetate copolymer, a silane-modified polyolefin elastomer, a silane-modified ethylene-methyl acrylate copolymer, a silane-modified ethylene-acrylic acid copolymer, and a silane-modified polymethyl methacrylate; further, the silane coupling agent is selected from at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy) silane, γ-aminopropyl triethoxysilane, γ-methacryloyloxypropyl trimethoxysilane, γ-glycidyloxypropyl trimethylsilane, and 3-aminopropyl trimethylsilane.

[0091] The initiator, co-crosslinking agent, and tackifier selected in the present application undergo a crosslinking reaction with the second matrix resin to achieve a high degree of crosslinking. The second bonding layer material obtained by the reaction can solve the problems of heat generated during operation of crystalline silicon cells, ice penetration, creep caused by rising component temperature, and the like.

[0092] According to the second aspect of the present application, a method for preparing the laminated battery packaging film is provided, including a melt extrusion method, a one-step molding method or a lamination and two-time lamination method:

[0093] Wherein, when the encapsulation film includes a first adhesive layer, a melt extrusion method is adopted: various raw materials are melted and mixed, and extruded into a film;

[0094] The one-step molding method is to use a cast double-layer co-extrusion method to form the film in one step, so that the two layers of film materials are stacked on each other to obtain a two-layer packaging film;

[0095] The double lamination method includes: firstly, one layer of film material is prepared by cast extrusion, and then another layer of molten raw material is poured on the surface of the first prepared film material by lamination lamination, and finally the two layers of film material are rolled to make the two layers of film material fit closely to obtain a two-layer packaging film.

[0096] The preparation method of the above-mentioned two-layer film of the present application also includes first placing the raw materials of the first adhesive layer and the raw materials of the second adhesive layer under screw extrusion for mixing and melting, and then selecting a one-step molding method or a two-time lamination method.

[0097] According to a third aspect of the present application, a laminated battery assembly is provided, comprising a laminated battery and a packaging film; wherein the packaging film is the above-mentioned laminated battery packaging film or the packaging film prepared by the above-mentioned preparation method.

[0098] In some embodiments, the two batteries in the stacked component are thin film batteries and crystalline silicon batteries; wherein the thin film batteries are selected from at least one of perovskite batteries, cadmium telluride batteries and copper indium gallium selenide batteries; more specifically, the stacked battery is a perovskite battery-crystalline silicon battery.

[0099] In some embodiments, Figure 1 As shown, the above-mentioned laminated battery assembly includes a front plate 1 (such as glass), a thin film battery 2, a front layer packaging film 3, a crystalline silicon battery 4, a rear layer packaging film 4 and a rear plate 5 (such as glass or a back plate) in sequence; wherein the front layer packaging film is the packaging film of the above-mentioned laminated battery or the packaging film obtained by the above-mentioned preparation method; further, the first adhesive layer of the front layer packaging film is tightly laminated with the thin film battery adjacent thereto.

[0100] In some embodiments, the second adhesive layer of the front encapsulation film is tightly laminated with the crystalline silicon cell adjacent thereto. In the present application, the first adhesive layer of the encapsulation film is arranged toward the thin-film cell, and the second adhesive layer is arranged toward the crystalline silicon cell; since the first adhesive layer material component is stable and has less reactive additives, the stability of the thin-film cell can be ensured when it is adjacent to the thin-film cell; since the second adhesive layer material has a high degree of cross-linking, when it is adjacent to the crystalline silicon cell, a series of problems such as creep caused by the increase in component temperature caused by the heat generated by the operation of the crystalline silicon cell can be reduced. According to the characteristics of thin-film batteries and crystalline silicon batteries, the present application first designs two adhesive layers that can better match thin-film batteries and crystalline silicon batteries respectively, and combines the different material properties and functions of the two adhesive layers to specifically laminate the first adhesive layer that does not contain small molecule additives with the thin-film battery to achieve the purpose of ensuring the stability of the thin-film battery, and then specifically laminates the second adhesive layer with cross-linking properties with the crystalline silicon battery to reduce a series of problems such as creep caused by the temperature rise of the components due to the heat generated during the operation of the crystalline silicon battery; and the two adhesive layer materials also have excellent barrier properties and insulation properties, which can avoid the problem of reduced battery efficiency due to the migration of small molecules and ions between the thin-film battery and the crystalline silicon battery.

[0101] In some embodiments, the laminate assembly may further include a front plate, a first encapsulation film, a thin film battery-crystalline silicon battery, a second encapsulation film and a back plate; wherein the first encapsulation film is the above-mentioned laminate battery encapsulation film or the above-mentioned encapsulation film. The encapsulation film is mainly used to ensure the stability of the thin film battery. Further, the first adhesive layer of the first encapsulation film is laminated with the thin film battery of the thin film battery-crystalline silicon battery; wherein the thin film battery-crystalline silicon battery is a battery in which a thin film battery and a crystalline silicon battery are integrally formed, which is a whole, and the first adhesive layer of the first encapsulation film is attached to the thin film battery to further ensure the structural stability of the battery.

[0102] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0103] The raw materials used in the examples of this application are all existing materials and can be purchased commercially.

[0104] Example 1

[0105] (1) The ingredients are prepared according to the raw material formula of each layer: in terms of mass percentage, the raw material of the first adhesive layer: 20% of ethylene-octene copolymer, 80% of silane-modified ethylene-octene copolymer; the raw material of the second adhesive layer: 95% of ethylene-vinyl acetate copolymer (EVA), 2.0% of butyl peroxyisopropyl carbonate, 2.0% of triallyl isocyanurate, and 1.0% of vinyl triethoxysilane; the thickness is 0.2 mm;

[0106] (2) The raw materials of each layer were melt-mixed in a screw extruder, and then cast double-layer co-extrusion was used to prepare a laminated battery encapsulation film in which the first adhesive layer and the second adhesive layer were tightly laminated and composited with each other. The thickness of the film was 0.4 mm. The film properties are shown in Table 1.

[0107] Example 2

[0108] The difference between Example 2 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0109] The raw materials of the first bonding layer: 50% ethylene-butene copolymer and 50% silane-modified ethylene-octene copolymer; the thickness of the first bonding layer is 0.2 mm;

[0110] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 96%, tert-butyl peroxycarbonate-2-ethylhexyl ester 1.5%, trimethylolpropane triacrylate 1.5%, and γ-aminopropyl triethoxysilane 1%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0111] Example 3

[0112] The difference between Example 3 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0113] The raw materials of the first bonding layer: 40% of ethylene-methyl acrylate copolymer and 60% of silane-modified ethylene-butylene copolymer; the thickness of the first bonding layer is 0.2 mm;

[0114] The raw materials of the second adhesive layer are: ethylene-octene copolymer 97%, 3,3,5-trimethylhexanoate tert-butyl peroxide 1.2%, pentaerythritol triacrylate 1.3%, vinyl triacetoxysilane 0.5%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0115] Example 4

[0116] The difference between Example 4 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0117] The raw materials of the first bonding layer: 30% of ethylene-methyl acrylate copolymer and 70% of silane-modified ethylene-vinyl acetate copolymer; the thickness of the first bonding layer is 0.2 mm;

[0118] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 98%, tert-amyl peroxide 2-ethylhexyl carbonate 0.7%, tris(2-hydroxyethyl)isocyanurate triacrylate 0.8%, and γ-methacryloyloxypropyltrimethoxysilane 0.5%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0119] Example 5

[0120] The difference between Example 5 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0121] The raw materials of the first bonding layer are: 20% polymethyl methacrylate and 80% silane-modified ethylene-octene; the thickness of the first bonding layer is 0.2 mm;

[0122] The raw materials of the second adhesive layer: ethylene-vinyl acetate copolymer 99%, tert-butyl peroxycarbonate-2-ethylhexyl ester 0.3%, ditrimethylolpropane tetraacrylate 0.6%, γ-glycidyloxypropyltrimethylsilane 0.1%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0123] Example 6

[0124] The difference between Example 6 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0125] Raw materials of the first bonding layer: 10% ethylene-vinyl acetate copolymer and 90% silane-modified ethylene-vinyl acetate copolymer; the thickness of the first bonding layer is 0.2 mm;

[0126] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 99.65%, tert-amyl peroxide 2-ethylhexyl carbonate 0.1%, triethylene glycol dimethacrylate 0.2%, and vinyl trimethoxysilane 0.05%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0127] Example 7

[0128] The difference between Example 7 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0129] The raw material of the first bonding layer: 100% silane-modified ethylene-butene copolymer; the thickness of the first bonding layer is 0.2 mm;

[0130] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 99.65%, tert-amyl peroxide 2-ethylhexyl carbonate 0.1%, triethylene glycol dimethacrylate 0.2%, and vinyl trimethoxysilane 0.05%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0131] Example 8

[0132] The difference between Example 8 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0133] Raw materials of the first adhesive layer: ethylene-vinyl acetate copolymer 20%, ethylene-butene copolymer 20%, silane-modified ethylene-octene copolymer 30%, silane-modified ethylene-butene copolymer 30%; the thickness of the first adhesive layer is 0.2 mm;

[0134] The raw materials of the second adhesive layer: 50% ethylene-vinyl acetate copolymer, 48% ethylene-butene copolymer, 0.5% tert-amyl peroxide 2-ethylhexyl carbonate, 1% polyethylene glycol dimethacrylate, and 0.5% vinyl trimethoxy silane; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0135] Example 9

[0136] The difference between Example 9 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0137] Raw materials of the first adhesive layer: ethylene-vinyl acetate copolymer 20%, ethylene-butene copolymer 20%, silane-modified ethylene-octene copolymer 30%, silane-modified ethylene-butene copolymer 30%; the thickness of the first adhesive layer is 0.2 mm;

[0138] The raw materials of the second adhesive layer: 50% ethylene-vinyl acetate copolymer, 48% ethylene-butene copolymer, 0.5% tert-amyl peroxide 2-ethylhexyl carbonate, 1% polyethylene glycol dimethacrylate, and 0.5% vinyl trimethoxy silane; the thickness of the second adhesive layer is 0.6 mm; the film properties are shown in Table 1.

[0139] Example 10

[0140] The difference between Example 10 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0141] Raw materials of the first adhesive layer: ethylene-vinyl acetate copolymer 20%, ethylene-butene copolymer 20%, silane-modified ethylene-octene copolymer 30%, silane-modified ethylene-butene copolymer 30%; the thickness of the first adhesive layer is 0.5 mm;

[0142] The raw materials of the second adhesive layer: 50% ethylene-vinyl acetate copolymer, 48% ethylene-butene copolymer, 0.5% tert-amyl peroxide 2-ethylhexyl carbonate, 1% polyethylene glycol dimethacrylate, and 0.5% vinyl trimethoxy silane; the thickness of the second adhesive layer is 0.2 mm; the film properties are shown in Table 1.

[0143] Embodiment 11

[0144] The difference between Example 11 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0145] Raw materials of the first adhesive layer: 10% ethylene-vinyl acetate copolymer, 10% ethylene-acrylic acid copolymer, 10% polymethyl methacrylate, 25% silane-modified ethylene-vinyl acetate copolymer, 25% silane-modified ethylene-octene copolymer, 20% silane-modified ethylene-butene; the thickness of the first adhesive layer is 0.3 mm;

[0146] The raw materials of the second adhesive layer: 40% ethylene-vinyl acetate copolymer, 30% ethylene-butene copolymer, 28% ethylene-octene copolymer, 0.5% tert-amyl peroxide 2-ethylhexyl carbonate, 1% polyethylene glycol dimethacrylate, and 0.5% vinyl trimethoxy silane; the thickness of the first adhesive layer is 0.3 mm; the film properties are shown in Table 1.

[0147] Example 12

[0148] The difference between Example 12 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0149] Raw materials for the first bonding layer: 50% ethylene-vinyl acetate copolymer, 50% silane-modified ethylene-vinyl acetate copolymer; photoconversion agent NaYF 4 -Yb 3+ The mass of the first bonding layer accounts for 0.5% of the total mass of the raw materials of the first bonding layer; the thickness of the first bonding layer is 0.3 mm;

[0150] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 96%, tert-amyl peroxide 2-ethylhexyl carbonate 1.5%, trimethylolpropane triacrylate 1.5%, γ-aminopropyl triethoxysilane 1%; the thickness of the second adhesive layer is 0.3 mm; the film properties are shown in Table 1.

[0151] Embodiment 13

[0152] The difference between Example 13 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0153] The raw materials of the first bonding layer: 50% ethylene-vinyl acetate copolymer and 50% silane-modified ethylene-vinyl acetate copolymer; the thickness of the first bonding layer is 0.3 mm;

[0154] Raw materials for the second bonding layer: ethylene-vinyl acetate copolymer 96%, tert-amyl peroxide 2-ethylhexyl carbonate 1.5%, trimethylolpropane triacrylate 1.5%, γ-aminopropyl triethoxysilane 1%; photoconversion agent GdOF-Yb 3+ / Er 3+ The mass of the second adhesive layer accounts for 2% of the total mass of the raw materials of the second adhesive layer; the thickness of the second adhesive layer is 0.3 mm; the film properties are shown in Table 1.

[0155] Embodiment 14

[0156] The difference between Example 14 and Example 1 is that the formulations of each layer are different; in terms of mass percentage,

[0157] Raw materials of the first bonding layer: 50% ethylene-vinyl acetate copolymer, 50% silane-modified ethylene-vinyl acetate copolymer; photoconversion agent BaTiO 3 -Yb 3+ / Tm 3+ The mass of the first bonding layer accounts for 0.8% of the total mass of the raw materials;

[0158] Raw materials for the second bonding layer: ethylene-vinyl acetate copolymer 96%, tert-amyl peroxide 2-ethylhexyl carbonate 1.5%, trimethylolpropane triacrylate 1.5%, γ-aminopropyl triethoxysilane 1%; photoconversion agent BaTiO 3 -Yb 3 + / Tm 3+ The mass of the second adhesive layer accounts for 0.7% of the total mass of the raw materials; the film properties are shown in Table 1.

[0159] Embodiment 15

[0160] The difference between Example 15 and Example 1 is that a PP barrier layer with a thickness of 0.1 mm is further included between the first adhesive layer and the second adhesive layer; in step (2), the raw materials of the first adhesive layer, the polypropylene barrier layer and the second adhesive layer are melt-kneaded separately, and then the first adhesive layer and the second adhesive layer are compounded on two opposite surfaces of the barrier layer by a cast-film bonding method to obtain a laminated battery encapsulation film in which the first adhesive layer, the barrier layer and the second adhesive layer are tightly laminated and compounded in sequence; the film properties are shown in Table 1.

[0161] Example 16

[0162] The difference between Example 16 and Example 15 is that the barrier layer material is polyamide; the film properties are shown in Table 1.

[0163] Embodiment 17

[0164] The difference between Example 17 and Example 15 is that the barrier layer material is polyethylene terephthalate; the film properties are shown in Table 1.

[0165] Embodiment 18

[0166] The difference between Example 18 and Example 1 is that the raw material formulas of each layer are different;

[0167] Raw materials of the first bonding layer: 65% ethylene-vinyl acetate copolymer and 35% silane-modified ethylene-vinyl acetate copolymer; the thickness of the first bonding layer is 0.2 mm;

[0168] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 97%, butyl peroxyisopropyl carbonate 2%, and vinyl triethoxysilane 1%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0169] Embodiment 19

[0170] The difference between Example 19 and Example 1 is that the raw material formulas of each layer are different;

[0171] The raw materials of the first bonding layer: 60% ethylene-vinyl acetate copolymer and 40% silane-modified ethylene-vinyl acetate copolymer; the thickness of the first bonding layer is 0.2 mm;

[0172] The raw materials of the second adhesive layer are: ethylene-vinyl acetate copolymer 90%, butyl peroxyisopropyl carbonate 2%, triallyl isocyanurate 4%, vinyl triethoxysilane 4%; the thickness of the second adhesive layer is 0.4 mm; the film properties are shown in Table 1.

[0173] Embodiment 20

[0174] The packaging film is a one-layer structure. The raw materials of the film are: 60% ethylene-vinyl acetate copolymer and 40% silane-modified ethylene-vinyl acetate copolymer. The thickness of the packaging film is 0.4 mm. The film properties are shown in Table 1.

[0175] Comparative Example 1

[0176] The encapsulation film is a one-layer structure. The raw materials of the film are: 97% ethylene-vinyl acetate copolymer, 2% butyl peroxyisopropyl carbonate, and 1% vinyl triethoxysilane. The film properties are shown in Table 1.

[0177] The performance of the encapsulation films of Examples 1 to 20 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0178] (1) Degree of crosslinking:

[0179] Take a piece of adhesive film. After peeling off the first adhesive layer and the second adhesive layer, refer to Standard GB / T 29848, "Ethylene-vinyl acetate copolymer (EVA) adhesive film for photovoltaic module encapsulation", to test the crosslinking degree of the second adhesive layer.

[0180] (2) Light transmittance:

[0181] The test method refers to Standard GB / T 29848, "Ethylene-vinyl acetate copolymer (EVA) adhesive film for photovoltaic module encapsulation". Note that when testing, ensure that the incident light first passes through adhesive layer 1 and then through adhesive layer 2.

[0182] (3) Adhesion to glass:

[0183] The test method refers to Standard GB / T 29848, "Ethylene-vinyl acetate copolymer (EVA) adhesive film for photovoltaic module encapsulation".

[0184] (4) Breakdown voltage:

[0185] The test method refers to Standard GB / T 1408.1-2016.

[0186] (5) Creep resistance:

[0187] As Figure 2 shown, take two pieces of float glass with dimensions of 300 mm × 300 mm × 2 mm (length × width × thickness), and a 300 mm × 270 mm encapsulation adhesive film 7'. Stack and laminate them in the order of the first glass 6' / encapsulation adhesive film 7' / second glass 8' with a dislocation, where the overlapping area of the first glass 6' and the second glass 8' is the same as the size of the encapsulation adhesive film 7'. Then fix the hook 4' on the surface of the first glass 6' through the structural adhesive 5'. After the structural adhesive 5' is completely cured, obtain Figure 2 the test sample as shown. Hang the test sample in an oven at 105°C for 15 days, and record the sliding distance of the second glass 8'.

[0188] (6) Mass percentage of volatile substances under the condition of 105°C:

[0189] Take a piece of adhesive film. After peeling off the first adhesive layer and the second adhesive layer, accurately weigh a sample of the first adhesive layer with a mass M1 (2.5 g < M1 < 3.5 g). After heating at 105°C for 10 min, cool it to room temperature in a desiccator and weigh it again. The mass is recorded as M2.

[0190] The mass percentage of volatile substances of the first adhesive layer under the condition of 105°C = (M1 - M2) / M1 × 100%.

[0191] (7) Exothermic enthalpy in the range of 130°C to 190°C:

[0192] Take a piece of adhesive film. After peeling off the first adhesive layer and the second adhesive layer, take a 7-10 mg sample of the first adhesive layer and perform DSC testing. Starting from room temperature, heat it to 230 °C at a heating rate of 10 °C / min, and integrally calculate the exothermic enthalpy between 120 and 190.

[0193] (8) Mass percentage of the substance dissolved in ethanol:

[0194] Take a piece of adhesive film. After peeling off the first adhesive layer and the second adhesive layer, weigh a sample of the first adhesive layer with a mass of M3 (4.5 g < M3 < 5.5 g), completely immerse it in 200 g of absolute ethanol, take it out after soaking at room temperature for 5 hours, dry it in a vacuum oven at 40 °C for 3 hours, and then take it out and weigh it, denoted as M4.

[0195] The mass percentage of the substance in the first adhesive layer dissolved in ethanol = (M3 - M4) / M3 × 100%.

[0196] Table 1

[0197]

[0198]

[0199] The test results of the performance of the encapsulation adhesive film in Table 1 show that the mass percentage of volatile substances in the first adhesive layer of the encapsulation adhesive films prepared in Examples 1-20 of the present application is less than 0.5% under the condition of a temperature of 105 °C, most of which are concentrated around 0.2%, and the mass percentage of the substances in the first adhesive layer dissolved in ethanol is less than 0.56%, most of which are concentrated between 0.2% and 0.4%; the encapsulation adhesive film has low volatility and low solubility, and the material components are stable, which can further ensure the stability of the thin-film battery, and has good barrier performance and insulation performance, and can avoid the problem of reduced battery efficiency caused by the migration of small molecules and ions between stacked batteries.

[0200] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those described herein.

[0201] The above are only the preferred embodiments of the present application, and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A laminated battery packaging film, characterized in that: The packaging film includes a first adhesive layer; the first adhesive layer at least meets one of the following conditions: (1) The mass percentage of volatile matter in the first adhesive layer at a temperature of 105° C. is less than 0.5%; (2) The mass percentage of the substance soluble in ethanol in the first adhesive layer is less than 1.0%.

2. The laminated battery packaging film according to claim 1, characterized in that: In terms of mass percentage, the raw materials of the first bonding layer include: 0% to 60% of the first base resin and 40% to 100% of the modified resin; Preferably, the mass percentage of the first base resin is 5% to 60%, and the mass percentage of the modified resin is 40% to 95%; further preferably, the mass percentage of the first base resin is 10% to 60%, and the mass percentage of the modified resin is 40% to 90%; Preferably, the first base resin is selected from at least one of ethylene-vinyl acetate copolymer, polyolefin elastomer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer and polymethyl methacrylate; Preferably, the polyolefin elastomer in the first base resin is selected from at least one of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer; Preferably, the modified resin is a silane-modified ethylene-vinyl acetate copolymer and / or a silane-modified polyolefin elastomer; Preferably, the silane-modified polyolefin elastomer is selected from at least one of a silane-modified ethylene-octene copolymer, a silane-modified ethylene-hexene copolymer and a silane-modified ethylene-butene copolymer; Preferably, the first adhesive layer has an exothermic enthalpy of less than 1.0 J / g in a temperature range of 130° C. to 190° C.; Preferably, the melting point of the first adhesive layer is 70°C to 120°C, and the melt index is ≤10g / 10min; Preferably, the thickness of the first adhesive layer is 0.2 to 0.5 mm; Preferably, the light transmittance of the first bonding layer is greater than or equal to 85%.

3. The laminated battery packaging film according to claim 1 or 2, characterized in that: The packaging film further includes a second adhesive layer stacked with the first adhesive layer; In terms of mass percentage, the raw materials of the second bonding layer include: 95% to 99.65% of the second base resin, 0.1% to 2% of the initiator, 0.2% to 2% of the auxiliary cross-linking agent, and 0.05% to 1% of the tackifier; Preferably, the second base resin is ethylene-vinyl acetate copolymer and / or polyolefin elastomer; Preferably, the polyolefin elastomer in the second base resin is selected from at least one of ethylene-octene copolymer, ethylene-hexene copolymer and ethylene-butene copolymer; Preferably, the thickness of the second adhesive layer is 0.2 to 0.6 mm; more preferably, it is 0.3 to 0.5 mm; Preferably, the light transmittance of the second adhesive layer is greater than or equal to 90%.

4. The laminated battery packaging film according to claim 3, characterized in that: A barrier layer is further provided between the first adhesive layer and the second adhesive layer; Preferably, the material of the barrier layer is selected from at least one of polyethylene terephthalate, polypropylene, polyethylene, polyamide, polycarbonate and polymethyl methacrylate; Preferably, the thickness of the barrier layer is 0.025 to 0.2 mm; more preferably, it is 0.05 to 0.2 mm; Preferably, the breakdown voltage of the barrier layer is greater than or equal to 25 kV / mm; Preferably, the light transmittance of the barrier layer is greater than or equal to 85%.

5. The laminated battery packaging adhesive film according to any one of claims 1 to 4, characterized in that: The raw materials of the first bonding layer and / or the second bonding layer further include a light conversion agent; Preferably, the photoconversion agent accounts for 0 to 2.0% of the total mass of the raw materials of the first bonding layer; more preferably, it accounts for 0.5% to 1.5%; Preferably, the photoconversion agent accounts for 0 to 2.0% of the total mass of the raw materials of the second bonding layer; more preferably, it accounts for 0.5% to 1.5%; Preferably, the light conversion agent is selected from light conversion agents having the function of converting infrared light into visible light; Preferably, the photoconverter is selected from an inorganic matrix doped with rare earth ions; Preferably, the rare earth ion doping method is selected from single doping, double doping or multi-doping; Preferably, the rare earth ion is selected from Er 3+ 、Ho 3+ 、Tm 3+ and Yb 3+ At least one of; Preferably, the inorganic matrix is ​​selected from at least one of fluorides, oxides, sulfur-containing compounds, oxyfluorides and halides; Preferably, the fluoride is selected from at least one of LiYF4, NaYF4, NaGdF4, BaY2F8 and CaF2; Preferably, the oxide is selected from at least one of Gd2O3, Y2O3, CeO2, Er2O3 and YVO4; Preferably, the sulfur-containing compound is selected from La2S3 and / or CaS; Preferably, the oxyfluoride is selected from GdOF and / or YOF; Preferably, the halide is selected from at least one of ZnCl2, CdCl2 and Cs3Lu2Br9; Preferably, the photoconverter is selected from NaYF4-Yb 3+ 、GdOF-Yb 3+ / Er 3+ 、BaTiO3-Yb 3+ / Er 3+ 、BaTiO3-Yb 3+ / Tm 3+ 、La2O3-Yb 3+ / Er 3+ 、Y2O3-Yb 3+ / Er 3+ , Er 3+ Rare earth upconversion luminescent nanoparticles, KZnF3-Er 3+ 、Tm 3+ , Yb 3+ Rare earth upconversion luminescent nanoparticles, YLiF4-Er 3+ 、NaYF4-Er 3+ / Yb 3+ 、LiYF4-Yb 3+ / Er 3+ 、NaYF4-Yb 3+ / Tm 3+ 、NaYF4-Ho 3+ / Yb 3+ 、Ho 3+ / Yb 3+ Co-doped Gd2O3 and E 3+ / Yb 3+ At least one of the co-doped CeO2 nanowire upper conversion materials.

6. The laminated battery packaging adhesive film according to any one of claims 3 to 5, characterized in that: The initiator is selected from peroxides; Preferably, the peroxide is selected from at least one of butyl peroxycarbonate isopropyl, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate and peroxy-3,3,5-trimethyl tert-butyl hexanoate; and / or, the auxiliary crosslinking agent is selected from triallyl isocyanurate, triallyl cyanurate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanuric acid triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propoxylated glycerol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ditrimethylolpropane At least one of 2-butyl-2-ethyl-1,3-propylene glycol diacrylate, 2-butyl-2-ethyl-1,3-propylene glycol diacrylate, 2-butyl-2-ethyl-1,3-propylene glycol diacrylate, 2-butyl-2-ethyl-1,3-propylene glycol dimeth ... And / or, the tackifier is at least one selected from the group consisting of a silane coupling agent, a silane-modified ethylene-vinyl acetate copolymer, a silane-modified polyolefin elastomer, a silane-modified ethylene-methyl acrylate copolymer, a silane-modified ethylene-acrylic acid copolymer, and a silane-modified polymethyl methacrylate; Preferably, the silane coupling agent is selected from at least one of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl triperoxide tert-butyl silane, vinyl triacetoxysilane, vinyl tri(β-methoxyethoxy)silane, γ-aminopropyl triethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ-glycidyloxypropyl trimethylsilane and 3-aminopropyl trimethylsilane.

7. A method for preparing a laminated battery packaging adhesive film according to any one of claims 1 to 6, characterized in that: The preparation method is a melt extrusion method, a one-step molding method or a double lamination method: The melt extrusion method comprises: melting and mixing the raw materials, and extruding and molding to obtain a layer of the packaging film; The one-step molding method is to use a cast double-layer co-extrusion method to form the film in one step, so that two layers of film materials are stacked on each other to obtain the packaging film with a two-layer structure; The double lamination method includes: firstly preparing one layer of film material by cast extrusion, then laminating another layer of molten raw material on the surface of the first prepared film material by lamination, and finally rolling the two layers of film material to make the two layers of film material fit tightly to obtain the packaging film with a two-layer structure.

8. A laminated battery assembly, characterized in that: The laminated battery assembly comprises a laminated battery and a packaging film; wherein the packaging film is the laminated battery packaging film according to any one of claims 1 to 6 or the packaging film prepared by the preparation method according to claim 7.

9. The laminated battery assembly according to claim 8, characterized in that: The stacked battery is a thin film battery and a crystalline silicon stacked battery; Preferably, the thin film battery is selected from at least one of a perovskite battery, a cadmium telluride battery and a copper indium gallium selenide battery; Preferably, the stacked cells in the stacked cell assembly are perovskite cells-crystalline silicon cells.

10. The laminated battery assembly according to claim 8, characterized in that: The laminated battery assembly comprises a front plate, a thin film battery, a front layer packaging film, a crystalline silicon battery, a rear layer packaging film and a rear plate in sequence; wherein the front layer packaging film is the laminated battery packaging film according to any one of claims 1 to 6 or the packaging film prepared by the preparation method according to claim 7; Preferably, the first adhesive layer of the packaging film is laminated with the thin film battery adjacent thereto; Or, the laminated assembly comprises a front plate, a first encapsulation film, a thin film battery-crystalline silicon battery, a second encapsulation film and a back plate; wherein the first encapsulation film is the laminated battery encapsulation film according to any one of claims 1 to 6 or the encapsulation film prepared by the preparation method according to claim 7; Preferably, the first adhesive layer of the first packaging film is laminated with the thin film battery of the thin film battery-crystalline silicon battery; Preferably, the front plate is glass; Preferably, the rear panel is glass or a back panel.

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