Resin layer, aluminum plastic film and lithium ion battery

Abstract

The invention discloses a resin layer, an aluminum plastic film and a lithium ion battery, and belongs to the field of battery outer packaging.The differential scanning calorimetry curve spectrum of the resin layer at least has the following characteristics that the melting peak appearance temperature of the resin layer is 120-210 DEG C; and / or the integral delta Hf of the area enclosed by the melting peak of the resin layer and the base line is 54.8 J / g to 87.3 J / g; and / or, the crystallinity Xc of the resin layer is 26.2%-41.7%. The application finds that the migration of the slipping agent into the resin layer can be effectively inhibited and the thermal stability of the slipping agent in the resin layer can be improved by limiting the crystallinity Xc and other parameters of the resin layer in the range. When applied to the aluminum-plastic film, the composite material is beneficial to improving the friction coefficient, temperature resistance and stability and the forming performance of the aluminum-plastic film, and has wide application prospects.

Description

Technical Field

[0001] This application belongs to the field of battery packaging, specifically relating to a resin layer, an aluminum-plastic film, and a lithium-ion battery. Background Technology

[0002] Based on their packaging shape, lithium-ion batteries can be mainly divided into three categories: square, cylindrical, and pouch. Among them, pouch lithium-ion batteries use aluminum-plastic film as the outer shell. With their significant advantages such as large capacity, light weight, high safety, and strong plasticity, they have achieved rapid development and widespread application in 3C products, power fields, and energy storage fields.

[0003] In recent years, with the continuous pursuit of high energy density in the new energy market for soft-pack lithium-ion batteries, aluminum-plastic films need to possess excellent forming capabilities. To improve the forming performance of aluminum-plastic films, a slip layer is typically applied to both the outer substrate resin layer and the inner thermally bonded resin layer. This aims to reduce the coefficient of friction between the film and the forming mold during the forming process, thereby enhancing its forming capability through increased compensatory forming. However, in practical applications, during storage, transportation, and use, when the ambient temperature exceeds a certain range, the slip agent in the slip layer formed by the inner thermally bonded resin layer easily migrates into the resin layer. This phenomenon leads to slip layer failure, resulting in a significant increase in the coefficient of friction. Ultimately, this causes a decrease in the forming capability of the aluminum-plastic film due to insufficient compensatory forming, severely impacting its widespread application. Summary of the Invention

[0004] This application aims to at least partially solve one of the technical problems in related technologies. Therefore, the purpose of this application is to provide a resin layer, an aluminum-plastic film, and a lithium-ion battery. This application discovers that by limiting parameters such as the crystallinity Xc of the resin layer within the aforementioned range, the migration of the slip agent into the resin layer and the thermal stability of the slip agent in the resin layer can be effectively suppressed. When applied to aluminum-plastic films, this is beneficial for improving the temperature stability of their coefficient of friction and the molding performance of the aluminum-plastic film, showing broad application prospects.

[0005] The first aspect of this application discloses a resin layer. According to embodiments of this application, the differential scanning calorimetry (DSC) spectrum of the resin layer has at least the following characteristics: The melting peak elution temperature of the resin layer is 120℃~210℃; And / or, the integral ΔH of the area enclosed by the melting peak of the resin layer and the baseline. f The concentration ranges from 54.8 J / g to 87.3 J / g. And / or, the crystallinity X of the resin layer c The percentages ranged from 26.2% to 41.7%.

[0006] The resin layer of the above embodiments of this application demonstrates that by limiting parameters such as the crystallinity Xc of the resin layer within the aforementioned range, the migration of the slip agent into the interior of the resin layer can be effectively suppressed, and the thermal stability of the slip agent in the resin layer can be improved. When applied to aluminum-plastic films, this is beneficial for improving the temperature stability of their coefficient of friction and the molding performance of the aluminum-plastic film, showing broad application prospects.

[0007] In addition, the resin layer according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the X c It is 30% to 35%.

[0008] In some embodiments of this application, the melting peak elution temperature of the resin layer is 140°C to 190°C; Alternatively, the melting peak elution temperature of the resin layer is 150℃~180℃.

[0009] In some embodiments of this application, the ΔH f The values ​​range from 62.8 J / g to 73.3 J / g.

[0010] In some embodiments of this application, the raw materials for the resin layer include at least one of polyester resin, polyamide resin, polyolefin resin, epoxy resin, acrylic resin, fluorinated resin, polyurethane resin, silicone resin, and phenolic resin.

[0011] In some embodiments of this application, the polyolefin resin includes at least one of polyethylene, polypropylene, copolymers of polyethylene and polypropylene, poly(1-butene), poly(1-pentene), poly(1-hexene), poly(1-octene), and poly(4-methyl-1-pentene).

[0012] In some embodiments of this application, the thickness of the resin layer is 10 μm to 100 μm.

[0013] A second aspect of this application discloses an aluminum-plastic film. According to an embodiment of this application, the aluminum-plastic film includes: a first resin layer; and a first adhesive layer, a metal layer, a second adhesive layer, and a second resin layer sequentially located on the surface of the first resin layer; the first resin layer is the resin layer described in the first aspect. This significantly improves the molding performance of the aluminum-plastic film.

[0014] In addition, the aluminum-plastic film according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the raw material of the first adhesive layer includes at least one of modified polyolefin and epoxy resin; And / or, the raw material of the metal layer includes aluminum foil, the surface of which is covered with a passivation film; And / or, the raw material of the second adhesive layer includes at least one of polyurethane, polyisocyanate, polyimide resin, polyacrylate and fluorine resin; And / or, the raw material of the second resin layer includes at least one of nylon and polyester; And / or, the thickness of the first adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the metal layer is between 10 μm and 80 μm; And / or, the thickness of the second adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the second resin layer is between 10 μm and 40 μm.

[0015] A third aspect of this application discloses a lithium-ion battery, wherein the casing of the lithium-ion battery comprises the resin layer described in the first aspect or the aluminum-plastic film described in the second aspect. This significantly improves the safety performance and lifespan of the lithium-ion battery.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of the aluminum-plastic film provided in the embodiments of this application.

[0018] Explanation of reference numerals in the attached figures: 1-Second resin layer; 2-Second adhesive layer; 3-Metal layer; 4-First adhesive layer; 5-First resin layer. Detailed Implementation

[0019] The embodiments of this application are described in detail below, and the embodiments described below with reference to the accompanying drawings are merely exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] The aluminum-plastic film, from the outside in, consists of an outer substrate resin layer, an outer adhesive layer, an intermediate metal layer, an inner adhesive layer, and an inner thermally bonded resin layer. With the increasing popularity of soft-pack lithium-ion batteries, the application of aluminum-plastic film is becoming more widespread. However, current technologies have limited research on the migration patterns of slip agents in the inner thermally bonded resin layer, resulting in poor control. Consequently, the slip agent often rapidly migrates into the interior of the resin layer after forming a slip layer, leading to slip layer failure and ultimately causing an excessively high coefficient of friction and reduced formability of the aluminum-plastic film.

[0021] To address the above problems, the technical solution provided in this application is as follows: The first aspect of this application discloses a resin layer. According to embodiments of this application, the differential scanning calorimetry (DSC) spectrum of the resin layer has at least the following characteristics: The melting peak elution temperature of the resin layer is 120℃~210℃; And / or, the integral ΔH of the area enclosed by the melting peak of the resin layer and the baseline. f The concentration ranges from 54.8 J / g to 87.3 J / g. And / or, the crystallinity X of the resin layer c The percentages ranged from 26.2% to 41.7%.

[0022] The resin layer of the above embodiments of this application demonstrates that by limiting parameters such as the crystallinity Xc of the resin layer within the aforementioned range, the migration of the slip agent into the interior of the resin layer can be effectively suppressed, and the thermal stability of the slip agent in the resin layer can be improved. When applied to aluminum-plastic films, this is beneficial for improving the temperature stability of their coefficient of friction and the molding performance of the aluminum-plastic film, showing broad application prospects.

[0023] In the embodiments of this application, the differential scanning calorimetry (DSC) curve of the resin layer is a thermogram obtained by measuring the power difference (heat flow rate) between the sample and the reference material as a function of temperature or time using a differential scanning calorimeter (DSC) under programmed temperature control. The vertical axis represents heat flow rate (dH / dt, unit: mW), and the horizontal axis represents temperature (T) or time (t). This curve reflects the thermal effects of the material during heating or cooling, such as melting, crystallization, and glass transition. In actual operation, a differential scanning calorimeter (DSC) can be used, employing a two-stage heating method, and the test can be performed at a heating rate of 10℃ / min.

[0024] In the embodiments of this application, the aforementioned melting peak is represented on the DSC curve. The melting peak is a convex peak formed by the absorption of heat when the material changes from a solid (crystalline) state to a liquid (amorphous) state, which characterizes an increase in enthalpy (endothermic effect); its peak temperature reflects the melting characteristics of the material. Specifically, the melting peak temperature of the resin layer provided in this application can be 120°C, 125°C, 135°C, 140°C, 155°C, 165°C, 180°C, 190°C, 210°C, or any two of the above values, preferably 140°C to 190°C, and more preferably 150°C to 180°C.

[0025] In the embodiments of this application, the above-mentioned ΔH f ΔHf is expressed as the integral of the area enclosed by the melting peak and the baseline (i.e., enthalpy of fusion), with units of J / g, representing the heat absorbed during the melting process of the material. This value is directly proportional to the crystallinity of the material; the higher the crystallinity, the greater ΔHf. Specifically, ΔHf... fThe value can be 55J / g, 60J / g, 65J / g, 70J / g, 75J / g, 80J / g, 87.3J / g, or any two of the above values, preferably 62.8J / g to 73.3J / g.

[0026] In the embodiments of this application, the crystallinity X is as follows: c X represents the percentage of the mass (or volume) of a crystalline region relative to the total mass (or volume) of the material. The formula for calculation is: X c =ΔH f / ΔH f * ×100%; where ΔH f The enthalpy of melting of the sample, ΔH f * The theoretical enthalpy of melting for a 100% crystalline material (obtainable through literature review or extrapolation from DSC data). Specifically, this application provides the X of the resin layer. c It can be 26.2%, 30.5%, 35.0%, 38%, 41.7% or any range between any two of the above values, preferably 30% to 35%.

[0027] According to some specific embodiments of this application, the raw material of the resin layer includes at least one of polyester resin, polyamide resin, polyolefin resin, epoxy resin, acrylic resin, fluorinated resin, polyurethane resin, silicone resin and phenolic resin; preferably, it is a polyolefin resin, which includes at least one of polyethylene, polypropylene, copolymer of polyethylene and polypropylene, poly-1-butene, poly-1-pentene, poly-1-hexene, poly-1-octene and poly-4-methyl-1-pentene.

[0028] In some embodiments of this application, the thickness of the resin layer is 10μm to 100μm, for example, it can be 10μm, 20μm, 30μm, 40μm, 50μm, 55μm, 60μm, 70μm, 80μm, 90μm, 100μm or any range between two of the above values.

[0029] It should be noted that the method for preparing the resin layer provided in this application includes the following steps: 1) obtaining commercially available resin materials that meet the thickness requirements; 2) heat-treating the existing resin materials. Therefore, this application achieves control over the range of Xc of the resin layer's crystallinity by performing secondary processing on existing known materials, specifically by precisely controlling the crystallization temperature and time of the resin layer through heat treatment, thereby realizing the design of the resin layer's crystallinity.

[0030] A second aspect of this application discloses an aluminum-plastic film. According to embodiments of this application, such as... Figure 1As shown, the aluminum-plastic film includes: a first resin layer 5; and a first adhesive layer 4, a metal layer 3, a second adhesive layer 2, and a second resin layer 1 sequentially located on the surface of the first resin layer 5; the first resin layer 5 is the resin layer described in the first aspect. This significantly improves the molding performance of the aluminum-plastic film.

[0031] Based on the existing aluminum-plastic film structure (composed from the outside to the inside as an outer substrate resin layer, an outer adhesive layer, an intermediate metal layer, an inner adhesive layer, and an inner heat-welding resin layer), this application adopts the resin layer described in the first aspect as the inner heat-welding resin layer (i.e., the first resin layer). By designing the crystallinity of the resin layer, the migration of the slip agent in the inner heat-welding resin layer is effectively controlled, the stability of the slip agent in the inner heat-welding resin layer is improved, and the stability of the friction coefficient of the inner heat-welding resin layer is increased, thereby improving the formability of the aluminum-plastic film. This solves the problem that in the prior art, the slip agent often fails due to rapid migration to the interior of the resin layer after forming a slip layer in the inner heat-welding resin layer, ultimately resulting in an excessively high friction coefficient and reduced formability of the aluminum-plastic film. Specifically, the second resin layer 1 (i.e., the outer substrate resin layer) and the middle metal layer 3 are bonded together by dry lamination of the second adhesive layer 2 (i.e., the outer adhesive layer), and the metal layer 3 is bonded together by dry lamination of the first resin layer 5 (i.e., the inner thermo-fusion resin layer) through the first adhesive layer 4 (i.e., the inner adhesive layer), or the first resin layer 5 (i.e., the inner thermo-fusion resin layer) is bonded together by hot lamination of the metal layer 3 by co-extrusion casting onto the surface of the middle metal layer 3.

[0032] According to some specific embodiments of this application, the raw material of the first adhesive layer includes at least one of modified polyolefin and epoxy resin; And / or, the raw material of the metal layer includes aluminum foil, the surface of which is covered with a passivation film; And / or, the raw material of the second adhesive layer includes at least one of polyurethane, polyisocyanate, polyimide resin, polyacrylate and fluorine resin; And / or, the raw material of the second resin layer includes at least one of nylon and polyester; And / or, the thickness of the first adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the metal layer is between 10 μm and 80 μm; And / or, the thickness of the second adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the second resin layer is between 10 μm and 40 μm.

[0033] It should be noted that the aluminum-plastic film provided in this application is prepared by the following method: the inner side of the second resin layer and the outer side of the metal layer are bonded together by dry lamination with a second adhesive layer; the inner side of the metal layer and the outer side of the first resin layer are bonded together by dry lamination with a first adhesive layer; and a slip agent is applied to the surface of the first resin layer. This significantly improves the molding performance of the aluminum-plastic film.

[0034] A third aspect of this application discloses a lithium-ion battery, wherein the casing of the lithium-ion battery comprises the resin layer described in the first aspect or the aluminum-plastic film described in the second aspect. This significantly improves the safety performance and lifespan of the lithium-ion battery.

[0035] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0036] Example 1 This embodiment provides an aluminum-plastic film, the structure of which, from the inside out, includes a first resin layer, a first adhesive layer, a metal layer, a second adhesive layer, and a second resin layer. The thickness of the first resin layer is 40 μm. The material of the first resin layer includes polypropylene. The preparation method of the first resin layer includes the following steps: heat-treating commercially available polypropylene material at 100°C for 72 hours, followed by natural cooling to obtain heat-treated polypropylene; coating the heat-treated polypropylene to a preset thickness and vacuum drying to obtain the first resin layer. The heat-treated polypropylene, using a differential scanning calorimeter (DSC) with a two-stage heating method and a heating rate of 10°C / min, exhibits a melting peak in the range of 160°C to 180°C; the enthalpy of fusion is 87.3 J / g, and the crystallinity is 41.7%. A first adhesive layer, a metal layer, a second adhesive layer, and a second resin layer are disposed on the surface of the first resin layer; The first adhesive layer is made of modified polyolefin and has a thickness of 3 μm; the metal layer is made of aluminum foil with a passivation film covering its surface and a thickness of 40 μm; the second adhesive layer is made of polyurethane and has a thickness of 5 μm; and the second resin layer is made of nylon and has a thickness of 25 μm.

[0037] The aforementioned aluminum-plastic film is prepared by the following method: The inner side of the second resin layer and the outer side of the metal layer are bonded together by dry bonding with the second adhesive layer, and the inner side of the metal layer and the outer side of the first resin layer are bonded together by dry bonding with the first adhesive layer. A slip agent is applied to the surface of the first resin layer to obtain an aluminum-plastic film.

[0038] Example 2 This embodiment provides an aluminum-plastic film and its preparation method, which differs from Embodiment 1 only in that: (1) The heat treatment process of the first resin layer material was adjusted. Specifically, the range of crystallization temperature of the resin layer was precisely controlled by adjusting the heat treatment temperature and time. The specific heat treatment temperature was adjusted to 90℃ and the time was adjusted to 60H. After heat treatment, the polypropylene was heated twice using a differential scanning calorimeter (DSC) at a heating rate of 10℃ / min. The melting peak appeared in the range of 150℃~180℃. The melting enthalpy was 70.5J / g and the crystallinity was 33.7%.

[0039] Example 3 This embodiment provides an aluminum-plastic film and its preparation method, which differs from Embodiment 1 only in that: (1) The heat treatment process of the first resin layer material was adjusted. Specifically, the range of crystallization temperature of the resin layer was precisely controlled by adjusting the heat treatment temperature and time. Specifically, the heat treatment temperature was adjusted to 80℃ and the time was adjusted to 24H. After heat treatment, the polypropylene was heated twice using a differential scanning calorimeter (DSC) at a heating rate of 10℃ / min. The melting peak appeared in the range of 150℃~180℃. The melting enthalpy was 54.8J / g and the crystallinity was 26.2%.

[0040] Example 4 This embodiment provides an aluminum-plastic film and its preparation method, which differs from Embodiment 1 only in that: (1) The thickness of the first resin layer is 80 μm.

[0041] Example 5 This embodiment provides an aluminum-plastic film and its preparation method, which differs from Embodiment 1 only in that: (1) The thickness of the first resin layer is 50 μm.

[0042] (2) The thickness of the second resin layer is 15 μm.

[0043] Comparative Example 1 This comparative example provides an aluminum-plastic film and its preparation method, which differs from Example 1 only in that: (1) The polypropylene material of the first resin layer was not heat-treated. The polypropylene without heat treatment was used with a differential scanning calorimeter (DSC) and a two-stage heating method. Under the heating rate of 10℃ / min, a melting peak appeared in the range of 150℃~180℃. The melting enthalpy was 38.9J / g and the crystallinity was 18.6%.

[0044] Comparative Example 2 This comparative example provides an aluminum-plastic film and its preparation method, which differs from Example 1 only in that: (1) The heat treatment process of the first resin layer material was adjusted. Specifically, the range of crystallization temperature of the resin layer was precisely controlled by adjusting the heat treatment temperature and time. The specific heat treatment temperature was adjusted to 120℃ and the time was adjusted to 96H. After heat treatment, the polypropylene was heated twice using a differential scanning calorimeter (DSC) at a heating rate of 10℃ / min. The melting peak appeared in the range of 150℃~180℃. The melting enthalpy was 112.1J / g and the crystallinity was 53.6%.

[0045] The characteristic parameters and thickness parameters of the differential scanning calorimetry curves of the first resin layer in the aluminum-plastic film provided in the above embodiments and comparative examples are shown in Table 1.

[0046] Table 1

[0047] Test case This test example performs performance tests on the aluminum-plastic films obtained in the above embodiments and comparative examples. The test method is as follows: A slip agent is applied to the surface of the first resin layer by coating, with a coating thickness of 0.01-0.1 μm; then, with the first resin layer of the aluminum-plastic film with the slip layer facing upwards, the aluminum-plastic film is placed in an oven at 25°C, 40°C, and 60°C for 7 days respectively. After removal, the friction coefficient of the first resin layer is tested using a friction testing machine. The mass of the slider is 200g.

[0048] The test results are shown in Tables 2 and 3.

[0049] Table 2. Test results of the coefficient of kinetic friction of the first resin layer in the examples and comparative examples.

[0050] Table 3. Static friction coefficient test results of the first resin layer in the examples and comparative examples.

[0051] As shown in Tables 2 and 3, when the polypropylene in the first resin layer is heated using a differential scanning calorimeter (DSC) with a two-stage heating method and a heating rate of 10℃ / min, a melting peak appears in the range of 150℃~180℃. When the enthalpy of melting is 54.8-87.3 J / g and the crystallinity is 26.2-41.7%, after the slip agent forms a slip layer on the surface of the polypropylene in the first resin layer, the slip agent is relatively stable on the polypropylene surface when the temperature is >40℃, which is reflected in a relatively stable coefficient of friction.

[0052] The test results of Comparative Example 1 show that: in the first resin layer, polypropylene, using differential scanning calorimetry (DSC) with a two-stage heating method and a heating rate of 10℃ / min, exhibits a melting peak in the range of 150℃~180℃. When the enthalpy of melting is 38.9 J / g and the crystallinity is 18.6%, after treatment at 40℃ for 7 days, the dynamic friction coefficient of the polypropylene surface increases by 115.3% and the static friction coefficient increases by 111.1% compared to the initial value. After treatment at 60℃ for 7 days, the dynamic friction coefficient of the polypropylene surface increases by 348.4% and the static friction coefficient increases by 316.0% compared to the initial value. The data indicate that after the slip agent forms a slip layer on the polypropylene surface, when the temperature is >40℃, the slip agent will rapidly migrate into the interior of the resin layer, causing the slip layer to fail. Ultimately, this will inevitably result in an excessively high friction coefficient and a reduced forming ability of the aluminum-plastic film.

[0053] The test results of Comparative Example 2 show that: when the polypropylene in the first resin layer is used with differential scanning calorimetry (DSC) and a two-stage heating method at a heating rate of 10℃ / min, a melting peak appears in the range of 150℃~180℃. When the enthalpy of melting is 112.1J / g and the crystallinity is 53.6%, the polypropylene surface of the aluminum-plastic film exhibits a high coefficient of friction in its original state. This is mainly because when the crystallinity of polypropylene exceeds a certain range, the film size shrinks during the cooling process, resulting in an uneven film surface, which leads to a sharp increase in film surface roughness, thus resulting in a high coefficient of friction and a reduced aluminum-plastic film forming ability.

[0054] The test results of Example 1 show that: in the first resin layer, polypropylene, using differential scanning calorimetry (DSC) with a two-stage heating method and a heating rate of 10℃ / min, exhibits a melting peak in the range of 160℃~180℃. When the enthalpy of melting is 87.3 J / g and the ratio of crystalline to amorphous regions (i.e., crystallinity) is 41.7%, after treatment at 40℃ for 7 days, the dynamic friction coefficient of the polypropylene surface increases by 7.2% and the static friction coefficient increases by 7.4% compared to the initial value. After treatment at 60℃ for 7 days, the dynamic friction coefficient of the polypropylene surface increases by 12.8% and the static friction coefficient increases by 14.2% compared to the initial value. The data indicates that after the slip agent forms a slip layer on the polypropylene surface, it remains relatively stable at temperatures above 40℃ and does not rapidly migrate into the resin layer, thus preventing slip layer failure. This significantly improves the stability of the polypropylene surface friction coefficient of the aluminum-plastic film, especially its stability under high-temperature conditions, which is a very beneficial guarantee for the molding ability of the aluminum-plastic film.

[0055] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0056] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A resin layer, characterized in that, The differential scanning calorimetry (DSC) curve of the resin layer has at least the following characteristics: The melting peak elution temperature of the resin layer is 120℃~210℃; And / or, the integral ΔH of the area enclosed by the melting peak of the resin layer and the baseline. f The concentration ranges from 54.8 J / g to 87.3 J / g. And / or, the crystallinity X of the resin layer c The percentages ranged from 26.2% to 41.7%.

2. The resin layer according to claim 1, characterized in that, The X c It is 30% to 35%.

3. The resin layer according to claim 1, characterized in that, The melting peak elution temperature of the resin layer is 140℃~190℃; Alternatively, the melting peak elution temperature of the resin layer is 150℃~180℃.

4. The resin layer according to claim 1, characterized in that, The ΔH f The values ​​range from 62.8 J / g to 73.3 J / g.

5. The resin layer according to any one of claims 1 to 4, characterized in that, The raw materials for the resin layer include at least one of polyester resin, polyamide resin, polyolefin resin, epoxy resin, acrylic resin, fluorinated resin, polyurethane resin, silicone resin, and phenolic resin.

6. The resin layer according to claim 5, characterized in that, The polyolefin resin includes at least one of polyethylene, polypropylene, copolymers of polyethylene and polypropylene, poly(1-butene), poly(1-pentene), poly(1-hexene), poly(1-octene), and poly(4-methyl-1-pentene).

7. The resin layer according to any one of claims 1 to 4, characterized in that, The thickness of the resin layer is 10μm to 100μm.

8. An aluminum-plastic film, characterized in that, include: First resin layer; as well as A first adhesive layer, a metal layer, a second adhesive layer, and a second resin layer are sequentially located on the surface of the first resin layer. The first resin layer is the resin layer according to any one of claims 1 to 7.

9. The aluminum-plastic film according to claim 8, characterized in that, The raw materials for the first adhesive layer include at least one of modified polyolefin and epoxy resin; And / or, the raw material of the metal layer includes aluminum foil, the surface of which is covered with a passivation film; And / or, the raw material of the second adhesive layer includes at least one of polyurethane, polyisocyanate, polyimide resin, polyacrylate and fluorine resin; And / or, the raw material of the second resin layer includes at least one of nylon and polyester; And / or, the thickness of the first adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the metal layer is between 10 μm and 80 μm; And / or, the thickness of the second adhesive layer is between 1 μm and 10 μm; And / or, the thickness of the second resin layer is between 10 μm and 40 μm.

10. A lithium-ion battery, characterized in that, The outer casing of the lithium-ion battery comprises a resin layer as described in any one of claims 1 to 7 or an aluminum-plastic film as described in any one of claims 8 to 9.

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