Blue film for battery, battery monomer, battery and electric device

Abstract

The utility model relates to a blue film for a battery, a battery monomer, a battery and an electric device. The blue film for the battery comprises a first insulating polymer base material, a flexible heat-insulating film layer and a second insulating polymer base material which are arranged in a laminated manner, wherein the flexible heat-insulating film layer is positioned between the first insulating polymer base material and the second insulating polymer base material. The first insulating polymer base material and the second insulating polymer base material not only can play a role in multi-insulation protection on the battery monomers, but also can play a role in protecting the flexible heat-insulating film layer to enable the flexible heat-insulating film layer to stably exert heat-insulating performance, so that the blue film for the battery has insulation and heat-insulating effects at the same time, and the blue film for the battery is used for the battery, thereby improving the utilization rate of the battery. And a good effect of preventing and delaying the thermal runaway of the battery can be achieved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a blue film for batteries, a battery cell, a battery and an electric device. Background Art

[0002] With the increasingly wide application of secondary batteries in the market, the requirements for the energy density of secondary batteries are also getting higher and higher. Subsequently developed are high-VED battery cells, which refer to battery cells with high volume energy density (VED). For example, in electric vehicles, using high-VED battery cells can increase the cruising range of the vehicle without increasing the volume of the battery pack. However, battery cells with higher energy density bring higher safety protection pressure. For example, after thermal runaway occurs, the temperature rises rapidly, the heat conduction increases rapidly, and adjacent batteries may also undergo thermal runaway successively, which may cause damage to the entire battery pack.

[0003] Therefore, how to prevent and delay battery thermal runaway is an urgent problem to be solved. Summary of the Utility Model

[0004] Based on this, in view of the problem of how to prevent and delay battery thermal runaway, it is necessary to provide a blue film for batteries, a battery cell, a battery and an electric device.

[0005] In the first aspect of the present application, a blue film for batteries is provided, including a first insulating polymer substrate, a flexible heat insulation film layer and a second insulating polymer substrate which are stacked, and the flexible heat insulation film layer is located between the first insulating polymer substrate and the second insulating polymer substrate.

[0006] For the above blue film for batteries, the flexible heat insulation film layer is arranged in the middle by using the first insulating polymer substrate and the second insulating polymer substrate, and the flexible heat insulation film layer is used for heat insulation. The first insulating polymer substrate and the second insulating polymer substrate can not only provide multiple insulation protections for the battery cell, but also protect the flexible heat insulation film layer to enable it to stably exert its heat insulation performance. In this way, the blue film for batteries has both insulation and heat insulation functions at the same time. Through this blue film, physical protection of insulation and anti-permeation and heat isolation effects can be simultaneously given to the battery cell; and because the blue film is closely attached to the battery cell, a relatively stable protection effect can be achieved. In this way, when the blue film for batteries is used in a battery, it can play a good role in preventing and delaying battery thermal runaway.

[0007] In any embodiment of the present application, the blue film for batteries is a coil material.

[0008] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0009] (1) The stiffness of the flexible heat insulation film layer ≥ 190 mm;

[0010] (2) The thickness of the flexible heat insulation film layer is 0.2 mm to 0.5 mm;

[0011] (3) The thermal conductivity of the flexible heat insulation film layer at 25 °C is 0.01 W / (m·K) to 0.03 W / (m·K).

[0012] Within this range of stiffness, the flexible heat insulation film layer has good flexibility, which is convenient for winding and can also be easily wrapped around the outside of the battery cell, better fitting with the battery cell.

[0013] Controlling the thickness of the flexible heat insulation film layer within this range can take into account good heat insulation effects while having a smaller thickness.

[0014] The flexible heat insulation film layer has a low thermal conductivity, so it can provide good heat insulation; taking into account the ultra-thin characteristics and efficient heat insulation effect.

[0015] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0016] (1) The stiffness of the flexible heat insulation film layer ≥ 195 mm;

[0017] (2) The thickness of the flexible heat insulation film layer is 0.2 mm to 0.35 mm;

[0018] (3) The thermal conductivity of the flexible heat insulation film layer at 25 °C is 0.01 W / (m·K) to 0.02 W / (m·K).

[0019] In any embodiment of the present application, the flexible heat insulation film layer includes a laminate of one or more of an organic support material heat insulation pad and an inorganic support material heat insulation pad.

[0020] In any embodiment of the present application, the organic support material heat insulation pad includes one or more of a porous silicon flexible heat insulation pad and a polymer aerogel heat insulation pad; the inorganic support material heat insulation pad includes a glass fiber cloth.

[0021] In any embodiment of the present application, the flexible heat insulation film layer includes a laminate of one or more of a porous silicon flexible heat insulation pad, a polymer aerogel heat insulation pad, and a glass fiber cloth.

[0022] The above-mentioned flexible heat insulation film layers all have good flexibility and heat insulation performance. Compared with the glass fiber cloth, the porous silicon flexible heat insulation pad and the polymer aerogel heat insulation pad have better flexibility and heat insulation performance, and can better fit with the insulating polymer substrate to form a flexible blue film.

[0023] In any embodiment of the present application, the polymer aerogel thermal insulation pad includes a laminate of one or more of a melamine aerogel thermal insulation pad, a PI aerogel thermal insulation pad, and a PET aerogel thermal insulation pad.

[0024] In any embodiment of the present application, the blue film for battery further includes a first adhesive layer and a release film. The release film is disposed on a side of the second insulating polymer substrate away from the flexible thermal insulation film layer, and the first adhesive layer is located between the second insulating polymer substrate and the release film.

[0025] Thus, during use, the release film can be removed to expose the first adhesive layer, and the blue film for battery can be adhered to a target position, such as the outer surface of a battery cell, through the first adhesive layer. In addition, when the blue film for battery is wound up, the release film can serve as an isolation between layers of the blue film, playing a role in preventing adhesion.

[0026] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0027] (1) The first adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer;

[0028] (2) The thickness of the first adhesive layer is 0.01 mm to 0.4 mm;

[0029] (3) The release film includes silicone release paper;

[0030] (4) The thickness of the release film is 0.05 mm to 0.2 mm.

[0031] These adhesive layers have strong adhesion, which can improve the overall peel strength of the blue film.

[0032] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0033] (1) The blue film for battery further includes a second adhesive layer, and the second adhesive layer is disposed between the first insulating polymer substrate and the flexible thermal insulation film layer; or, the first insulating polymer substrate is directly adhered to the flexible thermal insulation film layer;

[0034] (2) The blue film for battery further includes a third adhesive layer, and the third adhesive layer is disposed between the second insulating polymer substrate and the flexible thermal insulation film layer; or, the second insulating polymer substrate is directly adhered to the flexible thermal insulation film layer.

[0035] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0036] (1) The second adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer;

[0037] (2) The thickness of the second adhesive layer is 0.01 mm to 0.4 mm;

[0038] (3) The third adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer;

[0039] (4) The thickness of the third adhesive layer is 0.01 mm to 0.4 mm.

[0040] In any embodiment of the present application, one or more of the following conditions are satisfied:

[0041] (1) The first insulating polymer substrate includes one of a PI substrate, a PP substrate, and a PET substrate;

[0042] (2) The thickness of the first insulating polymer substrate is 0.01 mm to 0.15 mm;

[0043] (3) The second insulating polymer substrate includes one of a PI substrate, a PP substrate, and a PET substrate;

[0044] (4) The thickness of the second insulating polymer substrate is 0.01 mm to 0.15 mm.

[0045] In any embodiment of the present application, the total thickness of the blue film for battery is 0.2 mm to 2.0 mm.

[0046] In the second aspect of the present application, a battery cell is provided, including:

[0047] A housing having a receiving cavity;

[0048] An electrode assembly disposed in the receiving cavity; and,

[0049] The blue film for battery as provided in the first aspect of the present application, the blue film for battery is disposed on at least a part of the outer surface of the housing.

[0050] The blue film used in this battery cell can simultaneously provide physical protection of insulation and anti-permeation and thermal isolation for the battery cell; and because the blue film is closely attached to the battery cell, it can play a relatively stable protection role. In this way, the blue film for battery used in the battery can play a good role in preventing and delaying the thermal runaway of the battery.

[0051] In any embodiment of the present application, the blue film for battery is adhered to the housing through an adhesive layer disposed on the side of the second insulating polymer substrate away from the flexible heat insulation film layer.

[0052] In any embodiment of the present application, the housing includes a larger side wall, and the blue film for battery is disposed at least on the outer surface of the larger side wall.

[0053] In any embodiment of the present application, the housing includes a body and an end cap. The body includes a bottom plate and side plates connected to the bottom plate. The bottom plate and the side plates enclose a receiving cavity with an opening, and the end cap is used to seal the opening; the blue film for battery is disposed on all outer surfaces of the side plates, at least part of the outer surface of the bottom plate, and at least part of the outer surface of the end cap.

[0054] In a third aspect of the present application, there is provided a battery including the battery cell provided in the second aspect of the present application.

[0055] In a fourth aspect of the present application, there is provided an electrical device including at least one of the battery cell provided in the second aspect of the present application and the battery provided in the third aspect of the present application. Description of the Drawings

[0056] Figure 1 It is a schematic cross-sectional structure diagram of the blue film for battery in an embodiment of the present application;

[0057] Figure 2 It is a schematic overall structure diagram of the blue film for battery in an embodiment of the present application;

[0058] Figure 3 It is a schematic cross-sectional structure diagram of the blue film for battery in another embodiment of the present application;

[0059] Figure 4 It is a schematic cross-sectional structure diagram of the blue film for battery in another embodiment of the present application;

[0060] Figure 5 It is a schematic cross-sectional structure diagram of the blue film for battery in another embodiment of the present application;

[0061] Figure 6 It is a schematic structure diagram of a battery cell in an embodiment of the present application;

[0062] Figure 7 It is an exploded structure diagram of a battery cell in an embodiment of the present application;

[0063] Figure 8 It is a schematic diagram of a battery in an embodiment of the present application;

[0064] Figure 9 It is a schematic diagram of an electrical device powered by a battery in an embodiment of the present application.

[0065] Description of the Reference Numerals:

[0066] 100, Blue film for battery; 110, First insulating polymer substrate; 120, Second insulating polymer substrate; 130, Flexible heat insulating film layer; 141, First adhesive layer; 142, Second adhesive layer; 143, Third adhesive layer; 150, Release film;

[0067] 20, Battery cell; 200, Housing; 210, Body; 211, Side plate; 220, End cap; 300, Electrode assembly;

[0068] 30, Battery; 32, Heat insulating pad;

[0069] 40, Electrical device; 42, Controller; 44, Motor. Detailed implementation mode

[0070] To make the above objects, features, and advantages of the present application more apparent and understandable, the following describes the detailed implementation mode of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0071] In the description of the present application, it should be understood that if there appear these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application.

[0072] In addition, if there appear these terms "first", "second", these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if there appears the term "plurality", the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0073] In this application, unless otherwise clearly specified and defined, when a first feature is described as being "on" or "under" a second feature or similar descriptions, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0074] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0075] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way may or may not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values of 1 and 2 are listed, and if the maximum range values of 3, 4 and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4 and 2 - 5. In this application, unless otherwise stated, the numerical range "a - b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" have been fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when it is stated that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0076] At present, from the perspective of the development of the market situation, the application of batteries is becoming more and more widespread. Batteries, especially power batteries, are not only used in energy storage power systems such as hydraulic, thermal, wind, and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as other fields. With the continuous expansion of the application fields of power batteries, the market demand is also constantly increasing.

[0077] A battery cell (also known as a battery core) is the smallest unit that makes up a battery. A battery can include one or more battery cells, and multiple battery cells can be connected in series, parallel, or in a combination of series and parallel. Among them, a combination of series and parallel means that there are both series and parallel connections among multiple battery cells.

[0078] After multiple battery cells are connected to each other and arranged in a certain order, they can be directly placed in a box to assemble a battery. Or multiple battery cells can be first formed into a battery module, and then multiple battery modules are connected to each other to form a whole, and finally the whole of the battery module is placed in a box to form a battery.

[0079] In order to solve the above-mentioned battery thermal runaway problem and reduce the risk and degree of damage to the entire battery. In one or more embodiments of the present application, a blue film for a battery, a battery cell, a battery, and an electrical device are provided. Traditional blue films are generally composed of a polymer substrate and are pasted on the outside of the battery cell through an adhesive layer. Its main function is to insulate the battery cell, and in addition, it also plays a role in preventing electrolyte leakage. On the basis of retaining the insulation characteristics of the traditional blue film, the present application composes a heat insulation film layer to endow the blue film with heat insulation efficacy, and can simultaneously endow the battery cell with physical protection of insulation and anti-permeation and thermal isolation through the blue film; and because the blue film is closely attached to the battery cell, it can play a relatively stable protection role.

[0080] Please refer to Figure 1 , in the first aspect of the present application, a blue film 100 for a battery is provided, which includes a first insulating polymer substrate 110, a flexible heat insulation film layer 130, and a second insulating polymer substrate 120 that are stacked, and the flexible heat insulation film layer 130 is located between the first insulating polymer substrate 110 and the second insulating polymer substrate 120.

[0081] It can be understood that in the present application, the blue film can also be called an insulating protective film, and its color is not limited to blue, but blue is commonly used in the art.

[0082] The above blue film 100 for battery has a flexible heat insulation film layer 130 disposed in the middle by a first insulating polymer substrate 110 and a second insulating polymer substrate 120. The flexible heat insulation film layer 130 is used for heat insulation. The first insulating polymer substrate 110 and the second insulating polymer substrate 120 can not only provide multiple insulation protections for the battery cell, but also protect the flexible heat insulation film layer 130 to enable it to stably exert its heat insulation performance. In this way, the blue film 100 for battery has both insulation and heat insulation functions at the same time. Through the blue film 100 for battery, the battery cell 20 can be simultaneously given physical protections of insulation and anti-permeation and heat isolation functions; and because the blue film 100 for battery is closely attached to the battery cell 20, it can provide a relatively stable protection function. In this way, when the blue film 100 for battery is used for a battery, it can play a good role in preventing and delaying the thermal runaway of the battery.

[0083] By disposing the flexible heat insulation film layer 130 in the middle through the first insulating polymer substrate 110 and the second insulating polymer substrate 120, it is possible to prevent dust and electrolyte from leaking into the flexible heat insulation film layer 130, resulting in the problem that the heat insulation performance of the flexible heat insulation film layer 130 deteriorates significantly. Therefore, the flexible heat insulation film layer 130 can be protected to enable it to stably exert its heat insulation performance.

[0084] In some embodiments, the stiffness of the flexible heat insulation film layer 130 ≥ 190 mm; as an example, the stiffness of the flexible heat insulation film layer 130 can be 190 mm, 192 mm, 195 mm, 198 mm, 200 mm or any value within the range formed by any two of the above point values as the end values.

[0085] In this application, the test method for the stiffness of the flexible heat insulation film layer 130 is as follows. Ambient temperature: 22.8 °C, humidity: 56.4%RH, ambient temperature and humidity requirements: temperature 25 ± 3 °C, humidity 45% - 75%RH; referring to GB / T 7689.4-2013, specifically as follows: (1) Sample: size 250 mm * 50 mm * 1 mm, detect the initial thickness according to the method of 4.3.2 in GB / T 7689.4-2013; (2) Test method: The sample is placed flat on a high platform, one end of 50 mm is fixed on the platform, and the other end of 200 mm is suspended, and the sag height of the end of the suspended end is detected, that is, the stiffness is obtained.

[0086] The flexible heat insulation film layer 130 has good flexibility within this range. In this way, the blue film 100 for battery as a whole can have good flexibility and a relatively thin thickness, which is convenient for winding and can also be convenient for wrapping around the outside of the battery cell 20 to better fit with the battery cell 20. Further, the stiffness of the flexible heat insulation film layer 130 ≥ 190 mm. It can be understood that the blue film 100 for battery is a flexible film layer.

[0087] Please refer to Figure 2, in any embodiment of the present application, the blue film 100 for batteries is a roll material. The blue film 100 for batteries is a strip-shaped flexible film layer, and making it into a roll material is convenient for storage. When in use, the roll-shaped blue film 100 for batteries is opened into a strip shape and wrapped around the outside of the battery cell 20. Once wrapped, it can simultaneously insulate and heat-insulate the battery cell 20.

[0088] In any embodiment of the present application, the thickness of the flexible heat-insulating film layer 130 is 0.2 mm to 0.5 mm. Controlling the thickness of the flexible heat-insulating film layer 130 within this range can take into account good heat-insulating effects while having a relatively small thickness. As an example, the thickness of the flexible heat-insulating film layer 130 is 0.2 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, or any value within the range formed by any two of the above point values as the end values. Further, the thickness of the flexible heat-insulating film layer 130 is 0.2 mm to 0.35 mm.

[0089] In this article, the detection of the thickness of each part of the blue film 100 for batteries can be carried out by the following method. The equipment used is Mitutoyo 547-301 thickness gauge, and the accuracy of the equipment is ≤0.01 mm; during detection, it is required that the detection surfaces of the blue film 100 for batteries and the Mitutoyo 547-301 thickness gauge are both parallel to the ground. The detection positions are 5 places including four corners and the central area, and the average value of the 5 places is taken as the detection value.

[0090] In any embodiment of the present application, the thermal conductivity of the flexible heat-insulating film layer 130 at 25°C is 0.01 W / (m·K) to 0.03 W / (m·K). The flexible heat-insulating film layer 130 has a low thermal conductivity, so it can provide good heat-insulating effects; taking into account the ultra-thin characteristics and high-efficiency heat-insulating effects.

[0091] As an example, the thermal conductivity of the flexible heat-insulating film layer 130 at 25°C can be 0.01 W / (m·K), 0.015 W / (m·K), 0.02 W / (m·K), 0.025 W / (m·K), 0.03 W / (m·K), or any value within the range formed by any two of the above point values as the end values. Further, the thermal conductivity of the flexible heat-insulating film layer 130 at 25°C is 0.01 W / (m·K) to 0.02 W / (m·K).

[0092] In any embodiment of the present application, the flexible heat-insulating film layer 130 includes a laminate of one or more of an organic support material heat-insulating pad and an inorganic support material heat-insulating pad. Further, the organic support material heat-insulating pad includes, but is not limited to, one or more of a porous silicon flexible heat-insulating pad and a polymer aerogel heat-insulating pad; further, the inorganic support material heat-insulating pad includes, but is not limited to, glass fiber cloth. Further, the flexible heat-insulating film layer 130 includes a laminate of one or more of a porous silicon flexible heat-insulating pad, a polymer aerogel heat-insulating pad, and glass fiber cloth. The above flexible heat-insulating film layer 130 has a porous structure and all have good flexibility and heat-insulating performance. By disposing the flexible heat-insulating film layer 130 between the first insulating polymer substrate 110 and the second insulating polymer substrate 120, it is possible to prevent dust and electrolyte leakage from entering the porous structure of the flexible heat-insulating film layer 130, resulting in a significant deterioration of the heat-insulating performance of the flexible heat-insulating film layer 130. Therefore, the flexible heat-insulating film layer 130 can be protected to stably exhibit its heat-insulating performance.

[0093] Further, the porous silicon flexible heat-insulating pad includes, but is not limited to, porous vacuum silicon heat-insulating cotton. The porous vacuum silicon heat-insulating cotton is a cross-linked sheet-like flexible heat-insulating material including a polymer skeleton and nano-porous vacuum silica. Further, the porous vacuum silicon heat-insulating cotton is a flexible sheet heat-insulating material formed by combining a porous oxidized vacuum silicon material and a polymer skeleton material through a vacuum cross-linking gasification high-pressure drying preparation process.

[0094] When the flexible heat-insulating film layer 130 includes the above-mentioned multiple laminates, any two adjacent layers thereof can be bonded through an adhesive layer.

[0095] Compared with glass fiber cloth, the porous silicon flexible heat-insulating pad and the polymer aerogel heat-insulating pad have better flexibility and heat-insulating performance, and can better fit with the insulating polymer substrate to form a flexible blue film. Optionally, the flexible heat-insulating film layer 130 includes a laminate of one or more of a porous silicon flexible heat-insulating pad and a polymer aerogel heat-insulating pad. More optionally, the flexible heat-insulating film layer 130 includes a porous silicon flexible heat-insulating pad.

[0096] In some examples, the flexible heat-insulating film layer 130 is a laminate of one or more of a porous silicon flexible heat-insulating pad, a polymer aerogel heat-insulating pad, and glass fiber cloth.

[0097] Among them, the polymer aerogel heat-insulating pad includes, but is not limited to, a laminate of one or more of a melamine aerogel heat-insulating pad, a PI aerogel heat-insulating pad (i.e., a polyimide aerogel heat-insulating pad), and a PET aerogel heat-insulating pad (a polyethylene terephthalate aerogel heat-insulating pad). When the polymer aerogel heat-insulating pad includes the above-mentioned multiple laminates, any two adjacent layers thereof can be bonded through an adhesive layer.

[0098] Please refer to Figure 3, in any embodiment of the present application, the blue film 100 for battery further includes a first adhesive layer 141 and a release film 150. The release film 150 is disposed on the side of the second insulating polymer substrate 120 away from the flexible heat insulation film layer 130, and the first adhesive layer 141 is located between the second insulating polymer substrate 120 and the release film 150. That is, the first adhesive layer 141 adheres the release film 150 to one side of the second insulating polymer substrate 120. In this way, when in use, the release film 150 can be removed to expose the first adhesive layer 141, and the blue film 100 for battery can be attached to a target position, such as the outer surface of the battery cell 20, through the first adhesive layer 141. In addition, when the blue film 100 for battery is wound up, the release film 150 can act as an isolation between layers of the blue film 100 for battery, playing a role in preventing adhesion.

[0099] Further, the first adhesive layer 141 includes, but is not limited to, one or more laminations of an acrylate pressure-sensitive adhesive layer (i.e., acrylic pressure-sensitive adhesive), a polyurethane adhesive layer, and a silicone adhesive layer. These adhesive layers have strong adhesion, which can improve the overall peel strength of the blue film 100 for battery. Optionally, the first adhesive layer 141 includes an acrylate pressure-sensitive adhesive layer. The first adhesive layer 141 is used to attach to the battery cell 20, and using an acrylate pressure-sensitive adhesive layer is beneficial for enhancing the adhesion to the battery cell 20. The silicone adhesive layer is resistant to high temperatures and has high structural strength.

[0100] Further, the thickness of the first adhesive layer 141 is 0.01 mm to 0.4 mm. As an example, the thickness of the first adhesive layer 141 is 0.01 mm, 0.02 mm, 0.03 mm, 0.035 mm, 0.036 mm, 0.04 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, or any value within the range formed by any two of the above point values as the end values. Optionally, the thickness of the first adhesive layer 141 is 0.01 mm to 0.036 mm.

[0101] Further, the release film 150 includes, but is not limited to, silicone release paper.

[0102] Further, the thickness of the release film 150 is 0.2 mm.

[0103] Please refer to Figure 4 or Figure 5 , in some embodiments of the present application, the blue film 100 for battery further includes a second adhesive layer 142. The second adhesive layer 142 is disposed between the first insulating polymer substrate 110 and the flexible heat insulation film layer 130. In this way, the first insulating polymer substrate 110 and the flexible heat insulation film layer 130 are attached through the second adhesive layer 142, which can improve the adhesion between the first insulating polymer substrate 110 and the flexible heat insulation film layer 130.

[0104] Or, please refer to Figure 1Or Figure 3 , in some embodiments of the present application, the first insulating polymer substrate 110 is directly adhered to the flexible heat insulating film layer 130, for example, directly pressed by means of hot pressing, etc., and the first insulating polymer substrate 110 is directly adhered to the flexible heat insulating film layer 130 under the action of hot pressing.

[0105] Please continue to refer to Figure 4 Or Figure 5 , in some embodiments of the present application, the blue film 100 for battery further includes a third adhesive layer 143, and the third adhesive layer 143 is disposed between the second insulating polymer substrate 120 and the flexible heat insulating film layer 130. In this way, the third adhesive layer 143 adheres the second insulating polymer substrate 120 and the flexible heat insulating film layer 130, and the adhesion between the second insulating polymer substrate 120 and the flexible heat insulating film layer 130 can be improved.

[0106] Alternatively, please refer to Figure 1 Or Figure 3 , in some embodiments of the present application, the second insulating polymer substrate 120 is directly adhered to the flexible heat insulating film layer 130, for example, directly pressed by means of hot pressing, etc., and the second insulating polymer substrate 120 is directly adhered to the flexible heat insulating film layer 130 under the action of hot pressing.

[0107] Further, the second adhesive layer 142 includes, but is not limited to, a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer.

[0108] Further, the third adhesive layer 143 includes, but is not limited to, a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer.

[0109] Further, the thickness of the second adhesive layer 142 is 0.01 mm to 0.4 mm; as an example, the thickness of the second adhesive layer 142 is 0.01 mm, 0.02 mm, 0.03 mm, 0.034 mm, 0.035 mm, 0.036 mm, 0.04 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm or any value within the range formed by any two of the above point values as the end values. Optionally, the thickness of the second adhesive layer 142 is 0.01 mm to 0.034 mm.

[0110] Further, the thickness of the third adhesive layer 143 is 0.01 mm to 0.4 mm. As an example, the thickness of the third adhesive layer 143 is 0.01 mm, 0.02 mm, 0.03 mm, 0.034 mm, 0.035 mm, 0.036 mm, 0.04 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, or any value within the range formed by any two of the above point values as the end values. Optionally, the thickness of the third adhesive layer 143 is 0.01 mm to 0.034 mm.

[0111] In any embodiment of the present application, the first insulating polymer substrate 110 includes one of a PI substrate (polyimide substrate), a PP substrate (polypropylene substrate), and a PET substrate (polyethylene terephthalate substrate). In any embodiment of the present application, the second insulating polymer substrate 120 includes one of a PI substrate, a PP substrate, and a PET substrate. Such insulating polymer substrates not only have good insulating properties but also have excellent acid and alkali resistance, corrosion resistance, high voltage resistance, and no residual glue and other characteristics. Therefore, the blue film 100 for the battery can be used not only as an insulating isolation film but also as an anti-adhesive film or a protective film.

[0112] In any embodiment of the present application, the thickness of the first insulating polymer substrate 110 is 0.01 mm to 0.15 mm; as an example, the thickness of the first insulating polymer substrate 110 is 0.01 mm, 0.02 mm, 0.025 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.1 mm, 0.15 mm, or any value within the range formed by any two of the above point values as the end values. Optionally, the thickness of the first insulating polymer substrate 110 is 0.025 mm to 0.05 mm.

[0113] In any embodiment of the present application, the thickness of the second insulating polymer substrate 120 is 0.01 mm to 0.15 mm. As an example, the thickness of the second insulating polymer substrate 120 is 0.01 mm, 0.02 mm, 0.025 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.1 mm, 0.15 mm, or any value within the range formed by any two of the above point values as the end values. Optionally, the thickness of the second insulating polymer substrate 120 is 0.025 mm to 0.05 mm.

[0114] In any embodiment of the present application, the total thickness of the blue film 100 for batteries is less than or equal to 2.0 mm, and further less than or equal to 1.0 mm. As an example, the total thickness of the blue film 100 for batteries is 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, 1.2 mm, 1.5 mm, 2.0 mm, or any value within the range formed by any two of the above point values as the end values. Further, the total thickness of the blue film 100 for batteries is 0.25 mm to 2.0 mm, and can be optionally 0.25 mm to 1.0 mm or 0.25 mm to 0.5 mm.

[0115] In Figure 1 or Figure 3 In specific examples, the first insulating polymer substrate 110 and the flexible heat insulating film layer 130 are directly adhered to each other, and the second insulating polymer substrate 120 and the flexible heat insulating film layer 130 are directly adhered to each other. Further, in Figure 3 In specific examples, the blue film 100 for batteries further includes a first adhesive layer 141 and a release film 150, and the first adhesive layer 141 adheres the release film 150 to one side of the second insulating polymer substrate 120. Further, the first adhesive layer 141 is an acrylate pressure-sensitive adhesive layer.

[0116] In Figure 4 or Figure 5 In specific examples, the blue film 100 for batteries further includes a second adhesive layer 142 and a third adhesive layer 143. The second adhesive layer 142 is provided between the first insulating polymer substrate 110 and the flexible heat insulating film layer 130, and the third adhesive layer 143 is provided between the second insulating polymer substrate 120 and the flexible heat insulating film layer 130. Further, in Figure 5 In specific examples, the blue film 100 for batteries further includes a first adhesive layer 141 and a release film 150, and the first adhesive layer 141 adheres the release film 150 to one side of the second insulating polymer substrate 120. Further, the first adhesive layer 141 is an acrylate pressure-sensitive adhesive layer; further, the second adhesive layer 142 and the third adhesive layer 143 are silicone adhesive layers.

[0117] Please refer to Figure 6 and Figure 7 , in the second aspect of the present application, a battery cell 20 is provided, including a housing 200, an electrode assembly 300, and the blue film 100 for batteries provided in the first aspect of the present application. The housing 200 has a receiving cavity. The electrode assembly 300 is disposed in the receiving cavity of the housing 200. The blue film 100 for batteries is disposed on at least a part of the outer surface of the housing 200.

[0118] The blue film 100 for batteries used in the battery cell 20 can simultaneously provide physical protection for insulating and preventing penetration and thermal isolation for the battery cell 20; and because the blue film 100 for batteries is closely attached to the battery cell 20, it can play a relatively stable protective role. Thus, when the blue film 100 for batteries is used for the battery cell 20, it can play a good role in preventing and delaying the thermal runaway of the battery.

[0119] It should be noted that in this application, the housing 200 refers to a structure that can be used to accommodate the electrode assembly 300. The "battery cell 20" refers to the basic unit that can realize the mutual conversion between chemical energy and electrical energy. The electrode assembly 300 refers to the component in the battery cell 20 that undergoes an electrochemical reaction to realize the mutual conversion between chemical energy and electrical energy, and one or more electrode assemblies 300 can be accommodated inside the housing 200 of the battery cell 20. Further, generally speaking, the battery cell 20 at least includes a positive electrode plate, a negative electrode plate, and an electrolyte. During the charging and discharging process of the battery, active ions are embedded and removed back and forth between the positive electrode plate and the negative electrode plate. The electrolyte plays a role in conducting active ions between the positive electrode plate and the negative electrode plate. Further, the electrode assembly 300 further includes a separator disposed between the positive electrode plate and the negative electrode plate. Further, taking the electrolyte as an example of the electrolytic solution, the electrolytic solution infiltrates the electrode assembly. The number of electrode assemblies 300 included in the battery cell 20 can be one or more, and those skilled in the art can select according to specific actual needs.

[0120] In any embodiment of this application, the blue film 100 for batteries is adhered to the housing 200 through a first adhesive layer 141 disposed on one side of the second insulating polymer substrate 120 away from the flexible heat insulation film layer 130.

[0121] In any embodiment of this application, the housing 200 includes a larger side wall, and the blue film 100 for batteries is at least disposed on the outer surface of the larger side wall.

[0122] In any embodiment of this application, the housing includes a body 210 and an end cap 220. The body 210 has a receiving cavity with one end open, and the end cap 220 is used for sealingly disposed at the opening of the receiving cavity to form a sealed space, isolating the internal environment of the body 210 from the external environment. The electrode assembly 300 is accommodated in the sealed space of the housing 200. The blue film 100 for batteries is at least disposed on the outer surface of the body 210. Further, the larger side wall of the housing 200 is the side wall of the body 210.

[0123] Further, the body 210 includes a bottom plate and a side plate 211 connected to the bottom plate. The bottom plate and the side plate enclose a receiving cavity with one end open; the blue film 100 for batteries is disposed on the entire outer surface of the side plate 211. Further, the blue film 100 for batteries is also disposed on at least a part of the outer surface of the bottom plate and at least a part of the outer surface of the end cap. Further, the larger side wall of the housing 200 is the side plate 211.

[0124] In a specific example, the strip-shaped blue film 100 for the battery is wound and wrapped around the entire outer surface of the side plate 211 of the main body 210 in the length direction; and the width of the blue film 100 for the battery is greater than the height of the side plate 211 of the main body 210. The blue film 100 for the battery covers the side plate of the main body 210, and the surplus parts at both ends in the width direction are respectively wrapped around at least part of the outer surface of the bottom plate and at least part of the outer surface of the end cover, so that the edges of the battery cell 20 can be better wrapped, and the effect of better preventing electrolyte leakage can be achieved.

[0125] In some embodiments, the blue film 100 for the battery covers part or all of the outer surface of the bottom plate.

[0126] It can be understood that the shape of the battery cell 20 includes but is not limited to square and cylindrical, that is, the shape of the housing 200 includes but is not limited to square and cylindrical. The blue film 100 for the battery can be arranged in a fitting manner according to the shape of the battery cell 20.

[0127] For example, Figure 6 and Figure 7 FIG. is a battery cell 20 with a square structure as an example. The battery cell 20 and the housing 200 are square in shape. The main body 210 of the housing 200 includes a bottom plate and four side plates 211 connected to the bottom plate. Two of the side plates 211 with larger areas form the two relatively larger side walls of the large surface of the battery cell 20. That is, the housing 200 includes the two relatively larger side walls that form the large surface of the battery cell 20. The blue film 100 for the battery is arranged on the outer sides of the two relatively larger side walls, as well as on part of the outer surface of the bottom plate and part of the outer surface of the end cover 220.

[0128] It can be understood that when two adjacent battery cells 20 are arranged, the relatively larger side walls are arranged opposite to each other.

[0129] It can be understood that if the battery cell 20 and the housing 200 are cylindrical in shape, the housing 200 includes a cylindrical side wall (i.e., the relatively larger side wall) that forms the large surface of the battery cell 20.

[0130] Furthermore, the housing 200 is a cuboid housing. The opening direction of the housing 200 is the height direction of the housing. In a specific example, one end of the housing 200 is open, and the open end is the top end. In a specific example, both ends of the housing are provided with openings, and the two openings are arranged opposite to each other along the height direction of the housing.

[0131] As a non-limiting example, the height of the housing 200 is 80 mm to 210 mm; as a non-limiting example, the length of the housing 200 is 90 mm to 240 mm; as a non-limiting example, the width of the housing 200 is 20 mm to 80 mm.

[0132] Further, the battery cell 20 and the housing 200 are rectangular parallelepiped housings. The side surface of the battery cell 20 with a larger area is perpendicular to the above-mentioned width direction, and this side surface with a larger area is the side surface formed by the two sides in the above-mentioned length direction and height direction.

[0133] Further, as a non-limiting example, the wall thickness of the housing is 0.5 mm to 0.8 mm.

[0134] Further, the housing 200 is an aluminum alloy housing; for example, a 3-series aluminum alloy housing or a 5-series aluminum alloy housing.

[0135] Further, the aluminum alloy of the 3-series aluminum alloy housing includes components with the following mass percentage contents: aluminum ≥ 99.6%, copper ≤ 0.05%, iron ≤ 0.35%, magnesium ≤ 0.03%, manganese ≤ 0.03%, silicon ≤ 0.25%, titanium ≤ 0.03%, vanadium ≤ 0.05%, zinc ≤ 0.05%, other single elements ≤ 0.03%.

[0136] Further, the aluminum alloy of the 5-series aluminum alloy housing includes components with the following mass percentage contents: aluminum ≥ 96.7%, 0.05% ≤ copper ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other single element components ≤ 0.05%, total components of other elements ≤ 0.15%.

[0137] Further, a pole post is protrudingly provided on the end cover 220. The pole post is a component used for electrically connecting with the electrode assembly 300 to conduct out the electric energy of the electrode assembly 300.

[0138] Further, during the connection process between the electrode assembly 300 and the pole post, since the area where the pole post can connect with the electrode assembly 300 is small, in order to enable the electrode assembly 300 to be stably connected with the pole post, a welding pressure ring is usually required. After setting the welding pressure ring, in order to increase the sealing performance between the pole post and the end cover 220, a sealing ring is also required. In addition, in order to prevent the electrode assembly 300 from directly contacting other positions on the end cover 220 except the pole post, it is also necessary to set upper plastic and lower plastic between the electrode assembly 300 and the end cover 220 for insulation.

[0139] In addition, since the electrode assembly 300 can be a stacked electrode assembly or a wound electrode assembly, that is, it is formed by laminating or winding multiple positive electrode sheets, negative electrode sheets and separator films, therefore, when the electrode assembly 300 is connected to the pole post, it is also connected in multiple layers simultaneously. In some embodiments, the area where the pole post can connect with the electrode assembly 300 is small. In order to enable the multi-layer structure of the electrode assembly 300 to be more completely connected to the pole post, an adapter plate can be set between the electrode assembly 300 and the pole post to achieve their mutual connection.

[0140] Please refer to Figure 8, in the third aspect of the present application, a battery 30 is provided, including the battery cell provided in the second aspect of the present application.

[0141] In some embodiments, the battery 30 further includes a box body, and the battery cells are placed inside the box body.

[0142] Furthermore, the battery 30 includes a plurality of battery cells, and at least one battery cell is the above-mentioned battery cell 20. In a specific example, all the plurality of battery cells are the above-mentioned battery cells 20.

[0143] The plurality of battery cells in the battery 30 can be connected in series, in parallel, or in a series-parallel combination. Among them, the series-parallel combination means that there are both series and parallel connections among the plurality of battery cells.

[0144] After the plurality of battery cells are connected to each other and arranged in a certain order, they can be directly placed inside the box body to assemble into a battery. Or the plurality of battery cells can first form a battery module, and then the plurality of battery modules are connected to each other to form a whole, and finally the whole of the battery module is placed inside the box body to form the battery 30.

[0145] In some embodiments, the battery 30 further includes a heat insulation pad 32, and the heat insulation pad 32 is disposed between adjacent battery cells 20 and / or between the heat insulation pad 32 and the inner wall of the box body.

[0146] In some embodiments, the heat insulation pad 32 is disposed outside the larger sidewall of the battery cell 20. Further, the heat insulation pad 32 is disposed between the larger sidewalls of two adjacent battery cells 20.

[0147] In the fourth aspect of the present application, an electrical device is provided, including at least one of the battery cell provided in the second aspect of the present application and the battery provided in the third aspect of the present application.

[0148] The above-mentioned battery can be used as the power source of the electrical device or as the energy storage unit of the electrical device. The electrical device can include mobile devices, electric vehicles, electric trains, ships, satellites, etc., but is not limited thereto. Among them, the mobile device can be, for example, a mobile phone, a laptop computer, etc.; the electric vehicle can be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but is not limited thereto.

[0149] As the electrical device, the battery cell or the battery can be selected according to its usage requirements.

[0150] Figure 9The electrical device 40 is taken as an example. The electrical device 40 is a vehicle, and the electrical device 40 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended electric vehicle, etc. A battery 30 is arranged inside the vehicle, and the battery 30 can be arranged at the bottom, the head or the tail of the vehicle. The battery 30 can be used for power supply of the vehicle. For example, the battery 30 can be used as the operating power source of the vehicle. The vehicle may further include a controller 42 and a motor 44, and the controller 42 is used to control the battery 30 to supply power to the motor 44. For example, it is used for the working power requirements during the start, navigation and driving of the vehicle.

[0151] In some embodiments of the present application, the battery 30 can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0152] In some embodiments of the present application, the electrical device 40 is a pure electric vehicle, a hybrid electric vehicle or a plug-in hybrid electric vehicle. In order to meet the high-power and high-energy density requirements of the electrical device 40 for the battery, a battery formed by multiple battery cells can be used as the power source.

[0153] The device as another example can be a mobile phone, a tablet computer, a laptop computer, etc. This device usually requires being thin and light, and a battery cell can be used as the power source.

[0154] The following are specific embodiments.

[0155] Hereinafter, embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application. For those not specified in the embodiments regarding specific technologies or conditions, they shall be carried out according to the technologies or conditions described in the literature in the art or according to the product specifications. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0156] Embodiment 1

[0157] The blue film for the battery in Embodiment 1, as Figure 5 shown, includes a first insulating polymer substrate 110, a second adhesive layer 142, a flexible heat-insulating film layer 130, a third adhesive layer 143, a second insulating polymer substrate 120, a first adhesive layer 141 and a release film 150 which are sequentially stacked.

[0158] Among them, the first insulating polymer substrate 110 and the second insulating polymer substrate 120 are PET substrates with a thickness of 0.05 mm;

[0159] The flexible heat insulation film layer 130 is a porous vacuum silicon heat insulation cotton with a thickness of 0.35 mm; the stiffness of the flexible heat insulation film layer 130 (test method same as above) is 195 mm; the thermal conductivity of the flexible heat insulation film layer at 25 °C is 0.018 W / (m·K);

[0160] The second adhesive layer 142 and the third adhesive layer 143 are silicone adhesive layers with a thickness of 0.035 mm;

[0161] The first adhesive layer 141 is an acrylate pressure-sensitive adhesive layer with a thickness of 0.034 mm;

[0162] The release film 150 is a silicone release paper with a thickness of 0.2 mm.

[0163] Example 2

[0164] It is basically the same as Example 1, except that the material of the flexible heat insulation film layer 130 is different, specifically a melamine aerogel heat insulation pad with a thickness of 0.35 mm.

[0165] Example 3

[0166] It is basically the same as Example 1, except that the material of the flexible heat insulation film layer 130 is different, specifically a fiberglass cloth with a thickness of 0.35 mm.

[0167] Comparative Example 1

[0168] It is basically the same as Example 1, except that the flexible heat insulation film layer 130 and the third adhesive layer 143 are omitted. The blue film for the battery in Comparative Example 1 includes a first insulating polymer substrate 110, a second adhesive layer 142, a second insulating polymer substrate 120, a first adhesive layer 141, and a release film 150 that are sequentially stacked.

[0169] The following are performance tests.

[0170] (1) Peel force test: GB / T 2792-2014: National Standard of the People's Republic of China, which stipulates the test method for the peel strength of adhesive tapes. Standard reference: ASTM D903 (Test for Peel Strength of Adhesives), ISO 8510 (Peel Strength of Medical Tapes).

[0171] Tear off the release film and attach the blue film to the surface of the substrate aluminum foil (aluminum foil size ≥ 100 mm × 100 mm). Principle of 180° peel test (standard method): Peel the blue film from the surface of the substrate at an angle of 180° at a constant speed, measure the peak force or average force of the peel force during the peeling process, and calculate the peel strength G = F / w (unit: N / mm).

[0172] Equipment: Universal material testing machine (such as Instron 5969), peeling fixture (ensuring a constant angle of 180°). Key parameters: Sample size: blue film width 10 - 25 mm. Peeling rate: usually 50 mm / min. Environmental control: Constant temperature and humidity (23°C ± 2°C, 50% RH ± 5%). The sample needs to be balanced in the environment for 24 hours before testing.

[0173] (2)Withstand voltage test: Refer to standard GB-T / 1408.1-2006; AC (alternating current): 3500V; DC (direct current): 4500V; Leakage current < 1mA. Before starting, confirm that all connections are correct, especially the grounding wire; Calibrate the instrument reading with a standard resistor to ensure measurement accuracy; Gradually increase the voltage until the target level, and closely monitor the changes of various indicators throughout the process; After completing the test, quickly reduce the voltage to zero and cut off the power supply. If the specimen does not break down within the specified time, it is judged as passing; Meeting the withstand voltage performance.

[0174] (3)Insulation resistance: Apply a DC voltage (DC1000V) to the device under test according to the pre-set voltage level. For large-capacity electrical equipment, due to the absorption phenomenon, that is, as the pressurization time increases, the insulation resistance value will also increase, so it is necessary to wait for a period of time (usually 60s) for the reading to stabilize before recording the final value, and read and record the resistance value after one minute.

[0175] (4)Shear strength: GB / T 7124-2008: Chinese national standard, which stipulates the determination method of the tensile shear strength of structural adhesives.

[0176] 1. Specimen preparation size: Usually rectangular or dumbbell-shaped, length ≥ 50 mm, width 10 - 25 mm, thickness consistent with the actual thickness of the blue film used (uniform). Conditioning: Place the specimen in a standard environment (23 ± 2°C, 50 ± 5%RH) for at least 24 hours before testing.

[0177] 2. Test equipment Universal testing machine: The accuracy needs to meet the standard requirements (such as ±1% load). Shear fixture: Select a single-shear or double-shear fixture according to the specimen type (ensure reliable fixation of the specimen and avoid slippage).

[0178] 3. Test procedure Install the specimen: Fix the blue film specimen in the fixture, ensuring that the shear plane is perpendicular to the force application direction. Set parameters: Loading rate: 3mm / min. Preloading: Apply a small load for preloading to eliminate the gap (such as 5 - 10N). Data recording: Record the maximum load (N) when the specimen breaks.

[0179] 4. Result calculation Shear strength formula: t = F / A. Where: F is the maximum load (N), A is the shear area (mm 2).

[0180] 5. Precautions Fixture alignment: Ensure that the force application direction is strictly parallel to the shear plane to avoid additional bending moments. Edge treatment: The shear edges of the specimens should be flat to avoid stress concentration. Repeatability: At least 5 specimens are required for each group of tests, and the average value is taken.

[0181] (5) Heating stage test method:

[0182] The test method is as follows: Heat the heating stage to 500 °C, continuously heat for 20 min and maintain this temperature. Install temperature sensing wires on two opposite faces of the blue film (a rectangle with a size of 100 mm × 100 mm), place the blue film on the heating stage, and press an aluminum plate on the blue film with a pressure of 3000 N.

[0183] Measure the temperatures of the two faces of the blue film within 20 min of continuous heating, and the heat insulation effect of the blue film can be judged. Among them, the face of the blue film that is in direct contact with the heating stage is the hot face, and the other face opposite to the hot face is the cold face. There are 3 temperature sampling points on each face, one is the center point, and the other two are symmetrically distributed with respect to the center point, and the distance from the center point is 15 mm; statistically calculate the average temperature of the temperature sampling points on each face at 20 min of continuous heating to obtain the temperature difference between the hot face and the cold face at 20 min of continuous heating.

[0184] The test results of the blue films prepared in each example are shown in Table 1.

[0185] Table 1

[0186]

[0187] In Comparative Example 1, since there is no heat insulation film layer, there is basically no temperature difference between the hot face and the cold face during 20 min of continuous heating on the heating stage. As can be seen from Table 1, compared with Comparative Example 1, the blue films prepared in the examples have good insulation and withstand voltage properties, and also have good shear strength and heat insulation properties.

[0188] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0189] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A blue film for a battery, characterized in that, It includes a first insulating polymer substrate, a flexible heat insulation film layer, and a second insulating polymer substrate which are stacked, and the flexible heat insulation film layer is located between the first insulating polymer substrate and the second insulating polymer substrate.

2. The blue film for a battery according to claim 1, wherein The blue film for battery is in the form of a coil.

3. The blue film for battery according to claim 1, characterized in that, Meet one or more of the following conditions: (1) The stiffness of the flexible heat insulation film layer ≥ 190 mm; (2) The thickness of the flexible heat insulation film layer is 0.2 mm to 0.5 mm; (3) The thermal conductivity of the flexible heat insulation film layer at 25 °C is 0.01 W / (m·K) to 0.03 W / (m·K).

4. The blue film for battery according to claim 3, wherein Meet one or more of the following conditions: (1) The stiffness of the flexible heat insulation film layer ≥ 195 mm; (2) The thickness of the flexible heat insulation film layer is 0.2 mm to 0.35 mm; (3) The thermal conductivity of the flexible heat insulation film layer at 25 °C is 0.01 W / (m·K) to 0.02 W / (m·K).

5. The blue film for battery according to claim 1, characterized in that, The flexible heat insulation film layer includes a laminate of one or more of an organic support material heat insulation pad and an inorganic support material heat insulation pad.

6. The blue film for a battery according to claim 5, wherein The organic support material heat insulation pad includes one or more of a porous silicon flexible heat insulation pad and a polymer aerogel heat insulation pad; the inorganic support material heat insulation pad includes a fiberglass cloth.

7. The blue film for battery according to any one of claims 1 to 6, characterized in that, The blue film for battery further includes a first adhesive layer and a release film. The release film is provided on the side of the second insulating polymer substrate away from the flexible heat insulation film layer, and the first adhesive layer is located between the second insulating polymer substrate and the release film.

8. The blue film for battery according to claim 7, wherein Meet one or more of the following conditions: (1) The first adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer; (2) The thickness of the first adhesive layer is 0.01 mm to 0.4 mm; (3) The release film includes an organosilicon release paper; (4) The thickness of the release film is 0.05 mm to 0.2 mm.

9. The blue film for battery according to any one of claims 1 to 6 and 8, characterized in that, Meet one or more of the following conditions: (1) The blue film for battery further includes a second adhesive layer, and the second adhesive layer is provided between the first insulating polymer substrate and the flexible heat insulation film layer; or, the first insulating polymer substrate is directly adhered to the flexible heat insulation film layer; (2) The blue film for battery further includes a third adhesive layer, and the third adhesive layer is provided between the second insulating polymer substrate and the flexible heat insulation film layer; or, the second insulating polymer substrate is directly adhered to the flexible heat insulation film layer.

10. The blue film for battery according to claim 9, characterized in that, Meet one or more of the following conditions: (1) The second adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer; (2) The thickness of the second adhesive layer is 0.01 mm to 0.4 mm; (3) The third adhesive layer includes a laminate of one or more of an acrylate pressure-sensitive adhesive layer, a polyurethane adhesive layer, and a silicone adhesive layer; (4) The thickness of the third adhesive layer is 0.01 mm to 0.4 mm.

11. The blue film for battery according to any one of claims 1 to 6, 8, and 10, characterized in that, Meet one or more of the following conditions: (1) The first insulating polymer substrate includes one of a PI substrate, a PP substrate, and a PET substrate; (2) The thickness of the first insulating polymer substrate is 0.01 mm to 0.15 mm; (3) The second insulating polymer substrate includes one of a PI substrate, a PP substrate, and a PET substrate; (4) The thickness of the second insulating polymer substrate is 0.01 mm to 0.15 mm.

12. The blue film for battery according to any one of claims 1 to 6, 8, and 10, characterized in that The total thickness of the blue film for the battery is 0.2 mm to 2.0 mm.

13. A battery cell, characterized in that, It includes: A housing having a receiving cavity; An electrode assembly disposed in the receiving cavity; And, The blue film for the battery according to any one of claims 1 to 12, and the blue film for the battery is disposed on at least a part of the outer surface of the housing.

14. The battery cell according to claim 13, characterized in that, The blue film for the battery is adhered to the housing through an adhesive layer disposed on the side of the second insulating polymer substrate away from the flexible heat-insulating film layer.

15. The battery cell according to claim 13 or 14, characterized in that, The housing includes a larger side wall, and the blue film for the battery is disposed on at least the outer surface of the larger side wall.

16. The battery cell according to claim 13 or 14, characterized in that, The housing includes a body and an end cap. The body includes a bottom plate and side plates connected to the bottom plate. The bottom plate and the side plates enclose a receiving cavity with an opening, and the end cap is used to seal the opening; The blue film for the battery is disposed on the entire outer surface of the side plates, at least a part of the outer surface of the bottom plate, and at least a part of the outer surface of the end cap.

17. A battery, characterized in that, It includes a battery cell according to any one of claims 13 to 16.

18. An electrical device, characterized in that, It includes at least one of the battery cell according to any one of claims 13 to 16 and the battery according to claim 17.

Images