Battery cover, electronic equipment, protective film and cover body structure

Abstract

The invention provides a battery cover and electronic equipment comprising the battery cover. Relates to the technical field of electronic products. The battery cover comprises a cover body and an anti-puncture layer, the puncture-resistant layer is arranged on one side, close to the battery, of the cover body; or the cover body comprises a resin matrix, and the puncture-resistant layer is arranged in the resin matrix, for example, the puncture-resistant layer is embedded in the resin matrix; moreover, the specific puncture strength of the puncture-resistant layer is greater than or equal to 1.0 N / mu m, and the puncture-resistant layer comprises biaxial orientation ultra-high molecular weight polyethylene. The puncture-resistant layer has higher specific puncture strength and lower density, so that the battery cover has the characteristics of ultra-thinness, thinness and high strength.

Description

Technical Field

[0001] This application relates to the field of electronic product technology, and more particularly to a battery cover, an electronic device including the battery cover, and a protective film and cover structure. Background Technology

[0002] As the demands for battery life in mobile phones, tablets, and other electronic devices increase, larger batteries are being used. To meet the strong demand for thinner and lighter electronic devices, battery covers are often made thinner. However, thinner battery covers often lack the strength to reliably protect the battery. For example, if an electronic device is dropped on a sharp object, the sharp point may penetrate the battery cover and puncture the battery, or the shattering of the battery cover may create fragments that could puncture the battery, potentially causing a short circuit, fire, or explosion. Summary of the Invention

[0003] This application provides a battery cover, a protective film, a cover structure, a method for preparing the protective film, a method for preparing the cover structure, and an electronic device including the battery cover. The main objective is to provide a high-strength, thin, puncture-resistant battery cover.

[0004] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0005] Firstly, this application provides a battery cover, which can be used in terminal electronic devices, such as mobile phones and tablets.

[0006] The battery cover includes a cover body and a puncture-resistant layer; the puncture-resistant layer is disposed on the side of the cover body near the battery, and / or the cover body includes a resin matrix, and the puncture-resistant layer is disposed in the resin matrix, such as the puncture-resistant layer being embedded in the resin matrix; and the puncture-resistant layer includes biaxially oriented ultra-high molecular weight polyethylene, and the specific puncture strength of the puncture-resistant layer is greater than or equal to 1.0 N / μm.

[0007] The puncture-resistant layer disposed in the battery cover includes biaxially oriented ultra-high molecular weight polyethylene and has a high specific puncture strength, such as greater than or equal to 1.0 N / μm. Compared with battery covers using epoxy glass fiber as the puncture-resistant layer, where the specific puncture strength of epoxy glass fiber is 0.1 N / μm to 0.2 N / μm, this application can significantly improve the puncture resistance of the battery cover.

[0008] In addition, when the puncture resistance of the puncture-resistant layer is significantly improved, the thickness of the puncture-resistant layer in this application is thinner than that of existing layers with the same puncture resistance (e.g., 100N). This allows for a reduction in the thickness of the battery cover, thus achieving an ultra-thin and high-strength battery cover.

[0009] In one feasible approach, the puncture-resistant layer is a membrane structure with a thickness of less than or equal to 150 μm. For example, the thickness of the membrane structure is greater than or equal to 50 μm and less than or equal to 100 μm.

[0010] For example, the puncture-resistant layer comprises biaxially oriented ultra-high molecular weight polyethylene (UHMWPE). The specific puncture strength of the biaxially oriented UHMWPE is greater than or equal to 1.0 N / μm. The puncture-resistant layer is a single-layer film structure with a thickness of less than or equal to 150 μm. In other words, the biaxially oriented UHMWPE provided in this application not only has a high specific puncture strength (e.g., greater than or equal to 1.0 N / μm) but can also be made thick, thereby enabling the puncture-resistant layer to achieve a certain puncture resistance, for example, a puncture resistance of over 100 N.

[0011] In one feasible manner, the tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the puncture-resistant layer material is less than or equal to 1.2 g / cm³. 3 .

[0012] Because the puncture-resistant layer has a high tensile strength, which can be greater than or equal to 350 MPa, the mechanical strength and reliability of the battery cover can be improved. In addition, the material of the puncture-resistant layer has a low density, which can also make the battery cover ultra-thin and light.

[0013] In one possible implementation, where the puncture-resistant layer is disposed on the side of the cover near the battery, the battery cover further includes: a first buffer layer and a second buffer layer; the puncture-resistant layer is disposed between the first buffer layer and the second buffer layer; the first buffer layer is disposed on the surface of the cover near the battery via an adhesive layer.

[0014] In this example, since the puncture-resistant layer is located on the side of the cover close to the battery, a first buffer layer and a second buffer layer are used to sandwich the puncture-resistant layer in the middle, which can play a buffering and protective role.

[0015] In one feasible approach, the thickness of the puncture-resistant layer can be between 50 μm and 150 μm. For example, the thickness of the puncture-resistant layer is 100 μm.

[0016] In one feasible approach, the thickness of the first or second buffer layer can be between 0.1 mm and 0.4 mm. For example, the thickness of the first or second buffer layer is 0.3 mm.

[0017] In one feasible approach, the thickness of the adhesive layer can range from 10 μm to 40 μm. For example, the thickness of the adhesive layer is 15 μm.

[0018] In one possible implementation, the first cushioning layer comprises at least one of foam, silicone, polyurethane, epoxy prepreg, or thermoplastic elastomer.

[0019] In one feasible approach, the materials of the first and second buffer layers can be the same or different.

[0020] In one possible implementation, the orthographic projection of the puncture-resistant layer onto the first buffer layer lies within the boundary of the first buffer layer; the orthographic projection of the puncture-resistant layer onto the second buffer layer lies within the boundary of the second buffer layer; and the first buffer layer is connected to the second buffer layer via an adhesive layer.

[0021] This can be understood as follows: the area of ​​the first buffer layer and the second buffer layer is larger than that of the puncture-resistant layer. The first buffer layer, which has a larger area, is connected to the cover through an adhesive layer. In other words, the puncture-resistant layer is connected to the cover by an adhesive layer with a larger area. This can improve the reliability of the connection between the puncture-resistant layer and the cover.

[0022] In one possible implementation, the portion of the first buffer layer that does not overlap with the puncture-resistant layer has a perforated structure, and / or the portion of the second buffer layer that does not overlap with the puncture-resistant layer has a perforated structure.

[0023] By creating a perforated structure on the first or second buffer layer, the weight of the buffer layer can be reduced, making the battery cover lighter.

[0024] In one possible implementation, the battery cover may also include another puncture-resistant layer and a third buffer layer; the other puncture-resistant layer is disposed between the second and third buffer layers.

[0025] This further enhances the strength of the battery cover.

[0026] In one possible implementation, where the puncture-resistant layer is disposed on the side of the cover near the battery, the battery cover also includes a buffer substrate; the puncture-resistant layer is disposed in the buffer substrate; the buffer substrate is disposed on the surface of the cover near the battery.

[0027] In this example, the material of the buffer matrix may include a polyurethane thermoplastic elastomer. The polyurethane thermoplastic elastomer can be directly connected to the cover by heating and pressurizing, which can further reduce the thickness of the battery cover.

[0028] In one feasible approach, the puncture-resistant layer contains a buffer matrix material.

[0029] In some feasible processes, the material of the buffer matrix can include polyurethane-type thermoplastic elastomers, and the puncture-resistant layer needs to have a certain porosity, for example, the porosity can be greater than 20%. The buffer matrix and the cover are connected by heating and pressurizing. The buffer matrix can penetrate into the puncture-resistant layer, improve the connection strength between the puncture-resistant layer and the buffer matrix, and avoid delamination.

[0030] In one feasible approach, the puncture-resistant layer is disposed within a resin matrix; the puncture-resistant layer contains material of the resin matrix.

[0031] In this example, the puncture-resistant layer is placed within the resin matrix of the cover, which can be understood as an embedded structure that is embedded inside the battery cover. This allows for further reduction in the thickness of the battery cover.

[0032] For example, in some optional processes, during the cover molding process, the puncture-resistant layer is sandwiched in the buffer layer. The material of the buffer layer can be the same as the material of the battery cover. In this way, the puncture-resistant layer is embedded in the buffer matrix and resin matrix of the same material in the battery cover.

[0033] In this example, to prevent the puncture-resistant layer from delaminating from the resin matrix, the puncture-resistant layer needs to have a certain porosity, for example, a porosity greater than 20%. When the temperature and pressure are increased, the resin matrix can penetrate into the puncture-resistant layer, thereby improving the bonding strength between the puncture-resistant layer and the resin matrix.

[0034] In one feasible manner, the puncture-resistant layer is disposed within a resin matrix; the resin matrix has a buffer matrix, the puncture-resistant layer is located within the buffer matrix, and the puncture-resistant layer contains the material of the buffer matrix.

[0035] In this example, the puncture-resistant layer is placed in the buffer base of the cover, which can be understood as an embedded structure embedded in the battery cover. This can further reduce the thickness of the battery cover.

[0036] For example, in some optional processes, during the cover molding process, the puncture-resistant layer is sandwiched in the buffer layer. The material of the buffer layer can be different from the material of the battery cover. In this way, the puncture-resistant layer is embedded in the buffer matrix, which is embedded in the resin matrix.

[0037] Secondly, this application also provides an electronic device that may include a battery and a battery cover as described in any of the above implementations, the battery cover being disposed on one side of the battery; the orthogonal projection of the puncture-resistant layer on the battery overlaps with at least a portion of the battery.

[0038] In the electronic device provided by this application, the battery cover for protecting the battery includes a puncture-resistant layer. Since the puncture-resistant layer has a high specific puncture strength, greater than or equal to 1.0 N / μm, this application can significantly improve the puncture resistance of the battery cover. In addition, when the puncture resistance of the puncture-resistant layer is significantly improved, compared with the existing puncture resistance (e.g., 100 N), the thickness of the puncture-resistant layer of this application is thinner, thereby reducing the thickness of the battery cover and achieving an ultra-thin, high-strength battery cover.

[0039] Thirdly, this application also provides a protective film that can be applied in electronic devices or in wireless base stations, such as microwave antenna covers.

[0040] The protective film includes a buffer structure and a puncture-resistant layer, with the puncture-resistant layer in contact with the buffer structure; the puncture resistance of the puncture-resistant layer is greater than or equal to 1.0 N / μm, and the puncture-resistant layer includes biaxially oriented ultra-high molecular weight polyethylene.

[0041] In the protective film provided in this application, the puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, which means that the specific puncture resistance layer has a large specific puncture strength. By placing this protective film in the back cover of the mobile phone, the puncture resistance of the back cover can be improved. In addition, because the specific puncture resistance layer has a large specific puncture strength, it can be made thinner under the same puncture force, thus reducing the thickness of the back cover.

[0042] In one feasible approach, the puncture-resistant layer is a membrane structure with a thickness of less than or equal to 150 μm. For example, the thickness of the membrane structure is greater than or equal to 50 μm and less than or equal to 100 μm.

[0043] For example, the puncture-resistant layer comprises biaxially oriented ultra-high molecular weight polyethylene (UHMWPE). The specific puncture strength of the biaxially oriented UHMWPE is greater than or equal to 1.0 N / μm. The puncture-resistant layer is a single-layer film structure with a thickness of less than or equal to 150 μm. In other words, the biaxially oriented UHMWPE provided in this application not only has a high specific puncture strength (e.g., greater than or equal to 1.0 N / μm) but can also be made thick, thereby enabling the puncture-resistant layer to achieve a certain puncture resistance, for example, a puncture resistance of over 100 N.

[0044] In one feasible manner, the tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the puncture-resistant layer material is less than or equal to 1.2 g / cm³. 3 .

[0045] Because the puncture-resistant layer has a high tensile strength, which can be greater than or equal to 350 MPa, the mechanical strength and reliability of the battery cover can be improved. In addition, the material of the puncture-resistant layer has a low density, which can also make the battery cover ultra-thin and light.

[0046] In one possible implementation, the buffer structure includes: a first buffer layer and a second buffer layer, with a puncture-resistant layer disposed between the first buffer layer and the second buffer layer; or, the buffer structure includes a buffer matrix, with the puncture-resistant layer disposed within the buffer matrix, the puncture-resistant layer containing the material of the buffer matrix.

[0047] One example is to sandwich the puncture-resistant layer between two buffer layers, and another example is to embed the puncture-resistant layer in the buffer matrix.

[0048] Fourthly, this application also provides a method for preparing a protective film, the method comprising:

[0049] The puncture-resistant layer is placed between the first buffer layer and the second buffer layer;

[0050] An adhesive layer is used to connect the first buffer layer and the second buffer layer, or the stacked first buffer layer, puncture-resistant layer and second buffer layer are heated and pressurized to melt the first buffer layer and the second buffer layer to form a buffer matrix, and the buffer matrix wraps the puncture-resistant layer.

[0051] The puncture-resistant layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture-resistant layer includes biaxially oriented ultra-high molecular weight polyethylene.

[0052] When preparing a protective film using this method, the puncture-resistant layer can be stacked between two buffer layers, and the two buffer layers can be bonded together to form a protective film. Alternatively, the stacked two buffer layers and the puncture-resistant layer can be heat-fused, and the puncture-resistant layer can be held in place after the buffer layers are heat-fused.

[0053] Because the puncture resistance of the puncture-resistant layer in this application is relatively high, greater than or equal to 1.0 N / μm, this application can significantly improve the puncture resistance of the protective film. In addition, when the puncture resistance of the puncture-resistant layer is significantly improved, compared with the existing puncture resistance (e.g., puncture resistance of 100 N), the thickness of the puncture-resistant layer in this application is thinner, thereby reducing the thickness of the protective film.

[0054] In one possible implementation, the porosity of the puncture-resistant layer is less than or equal to 30%.

[0055] Since the porosity of the puncture-resistant layer is less than or equal to 30%, the material of the buffer layer can enter the pores of the puncture-resistant layer during the hot-melt treatment, thereby increasing the connection strength between the buffer layer and the puncture-resistant layer and thus improving the strength of the entire protective film.

[0056] Fifthly, this application also provides a cover structure that can be applied in the field of battery pack protection, such as in the protective cover of a battery pack.

[0057] The cover structure may include: a resin matrix and a puncture-resistant layer disposed in the resin matrix, wherein the puncture-resistant layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture-resistant layer comprises biaxially oriented ultra-high molecular weight polyethylene.

[0058] In the cap structure provided by this application, the puncture resistance of the puncture-resistant layer is greater than or equal to 1.0 N / μm, which can significantly improve the puncture resistance of the cap structure. In addition, when the puncture resistance of the puncture-resistant layer is significantly improved, compared with the existing puncture resistance (e.g., 100 N), the thickness of the puncture-resistant layer of this application is thinner, thereby reducing the thickness of the cap structure and achieving an ultra-thin, high-strength cap structure. Furthermore, by placing the puncture-resistant layer in the resin matrix of the cap, the thickness of the cap structure is not increased.

[0059] In one feasible approach, the puncture-resistant layer is a membrane structure with a thickness of less than or equal to 150 μm. For example, the thickness of the membrane structure is greater than or equal to 50 μm and less than or equal to 100 μm.

[0060] For example, the puncture-resistant layer comprises biaxially oriented ultra-high molecular weight polyethylene (UHMWPE). The specific puncture strength of the biaxially oriented UHMWPE is greater than or equal to 1.0 N / μm. The puncture-resistant layer is a single-layer film structure with a thickness of less than or equal to 150 μm. In other words, the biaxially oriented UHMWPE provided in this application not only has a high specific puncture strength (e.g., greater than or equal to 1.0 N / μm) but can also be made thick, thereby enabling the puncture-resistant layer to achieve a certain puncture resistance, for example, a puncture resistance of over 100 N.

[0061] In one feasible manner, the tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the puncture-resistant layer material is less than or equal to 1.2 g / cm³. 3 .

[0062] Because the puncture-resistant layer has a high tensile strength, which can be greater than or equal to 350 MPa, the mechanical strength and reliability of the cover structure can be improved. In addition, the material of the puncture-resistant layer has a low density, which can also make the cover structure ultra-thin and lightweight.

[0063] In one possible implementation, the puncture-resistant layer contains a resin matrix material; or, the resin matrix has a buffer matrix, the resin matrix material and the buffer matrix material being different; the puncture-resistant layer is located within the buffer matrix, and the puncture-resistant layer contains a buffer matrix material.

[0064] For example, in some optional processes, during the cover molding process, the puncture-resistant layer is sandwiched in the buffer layer. The material of the buffer layer can be the same as the material of the battery cover. In this way, the puncture-resistant layer is embedded in the buffer matrix and resin matrix of the same material in the battery cover.

[0065] For example, in some optional processes, during the cover molding process, the puncture-resistant layer is sandwiched in the buffer layer. The material of the buffer layer can be different from the material of the battery cover. In this way, the puncture-resistant layer is embedded in the buffer matrix, which is embedded in the resin matrix.

[0066] Sixthly, this application also provides a method for preparing a cover structure, the method comprising:

[0067] The puncture-resistant layer is placed between the first buffer layer and the second buffer layer;

[0068] The stacked first buffer layer, puncture-resistant layer and second buffer layer are heated and pressurized to melt the first buffer layer and the second buffer layer to form a buffer matrix, and the buffer matrix wraps the puncture-resistant layer.

[0069] The structure containing the puncture-resistant layer and the buffer matrix is ​​placed in a mold, and resin material is injected into the mold to form a resin matrix, so that the resin matrix encapsulates the buffer matrix and the puncture-resistant layer.

[0070] The puncture-resistant layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture-resistant layer includes biaxially oriented ultra-high molecular weight polyethylene.

[0071] In the method for preparing the cover structure provided in this application, a membrane layer containing an anti-puncture layer can be prepared first, and then the membrane layer can be placed in a mold for preparing the shell to finally obtain a cover structure containing an anti-puncture layer.

[0072] Because the puncture resistance layer of this application has a high specific puncture strength, greater than or equal to 1.0 N / μm, this application can significantly improve the puncture resistance of the cap structure. In addition, when the puncture resistance of the puncture resistance layer is significantly improved, compared with the existing puncture resistance force (e.g., 100 N), the thickness of the puncture resistance layer of this application is thinner, thereby reducing the thickness of the cap structure, thus achieving an ultra-thin and high-strength cap structure. Furthermore, by placing the puncture resistance layer in the resin matrix of the cap, the thickness of the cap structure will not be increased.

[0073] In one feasible approach, the porosity of the puncture-resistant layer is less than or equal to 30%.

[0074] Since the porosity of the puncture-resistant layer is less than or equal to 30%, the material of the buffer layer can enter the pores of the puncture-resistant layer during the hot-melt treatment, thereby increasing the connection strength between the buffer layer and the puncture-resistant layer and thus improving the strength of the entire protective film.

[0075] In one feasible manner, the materials of both the first buffer layer and the second buffer layer comprise resin materials.

[0076] In other words, the material of the buffer layer can be the same as the material of the cover itself, which can avoid delamination. Attached Figure Description

[0077] Figure 1 This is an exploded view of a partial structure of an electronic device as exemplified in this application;

[0078] Figure 2 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0079] Figure 3 A top view of a battery cover provided in an embodiment of this application;

[0080] Figure 4 A top view of a buffer layer provided in an embodiment of this application;

[0081] Figure 5 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0082] Figure 6 This is a schematic diagram showing the structure after each step in the manufacturing process of a battery cover provided in this application embodiment is completed;

[0083] Figure 7 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0084] Figure 8 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0085] Figure 9 This is a schematic diagram showing the structure after each step in the manufacturing process of a battery cover provided in this application embodiment is completed;

[0086] Figure 10 This is a schematic diagram of the structure of a puncture-resistant layer provided in an embodiment of this application;

[0087] Figure 11 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0088] Figure 12 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0089] Figure 13 This is a schematic diagram showing the structure after each step in the manufacturing process of a battery cover provided in this application embodiment is completed;

[0090] Figure 14 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0091] Figure 15 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0092] Figure 16 This is a schematic diagram showing the structure after each step in the manufacturing process of a battery cover provided in this application embodiment is completed;

[0093] Figure 17 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0094] Figure 18 This is a schematic diagram of the structure of a battery cover provided in an embodiment of this application;

[0095] Figure 19 This is a schematic diagram illustrating the positional relationship between the puncture-resistant layer and the battery, provided in an embodiment of this application.

[0096] Figure 20 This is a schematic diagram illustrating the positional relationship between the puncture-resistant layer and the battery, provided in an embodiment of this application.

[0097] Figure label:

[0098] 100 - Display screen; 200 - Back cover, battery cover; 300 - Middle frame; 400 - Battery; 201 - Cover body, resin matrix; 11, 12, 13 - Puncture-resistant layer; 21 - First buffer layer; 22 - Second buffer layer; 23 - Third buffer layer; 31, 32, 33 - Adhesive layer; 2 - Buffer matrix; 4 - Hollow structure; 5 - Mold. Detailed Implementation

[0099] The following embodiments of this application will be described in conjunction with the accompanying drawings.

[0100] This application provides an electronic device that can have a display function. This electronic device can be applied to various communication systems or protocols, such as Bluetooth (BT) communication technology, Global Positioning System (GPS) communication technology, Global System for Mobile Communication (GSM) communication technology, Wireless Fidelity (WiFi) communication technology, Wideband Code Division Multiple Access (WCDMA) communication technology, Long Term Evolution (LTE) technology, 5G communication technology, and other future communication technologies.

[0101] The electronic devices in this application embodiment can be mobile phones, tablets, laptops, smart home devices, smart wearable devices (e.g., smartwatches, smart bracelets, smart glasses, smart helmets), virtual reality (VR) electronic devices, augmented reality (AR) electronic devices, etc. Electronic devices can also be handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, electronic devices in 5G networks, or electronic devices in future evolved public land mobile networks (PLMNs), etc., and this application embodiment is not limited to these categories.

[0102] like Figure 1 As shown in the embodiments of this application, taking a mobile phone as an example, the electronic device may include a display screen 100, a back cover 200 located on the back of the display screen 100 (distributed opposite to the display surface of the display screen 100), and a mid-frame 300 located between the display screen 100 and the back cover 200. The mid-frame 300 can support the display screen 100.

[0103] The display screen 100 can be a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a micro (or mini) light-emitting diode (LED) display, or a quantum dot light-emitting diode (QLED) display, etc. This application does not limit the type of the above-mentioned display screen.

[0104] The aforementioned electronic device may also include at least one of the following: a processor electrically connected to the display screen 100, a sensor, a memory, a charging management module, a power management module, an antenna, a mobile communication module, a wireless communication module, an audio module, a speaker, a receiver, a microphone, a headphone jack, and a camera electrically connected to the processor.

[0105] like Figure 1 The electronic device may also include a battery 400, which can power some components in the electronic device. The battery 400 is disposed between the display screen 100 and the back cover 200, which may also be referred to as the battery cover 200.

[0106] To meet the strong demand for thinner and lighter terminal electronic devices, battery covers are typically made thinner. However, thinner battery covers often lack the strength to reliably protect the battery. This application provides examples of battery cover structures that are puncture-resistant and feature high strength and a thin design.

[0107] Figure 2 This is a schematic diagram of a battery cover 200 according to an embodiment of this application. In this example, the battery cover 200 includes a cover body 201, which may have opposing outer and inner surfaces, with the inner surface close to the battery and the outer surface away from the battery. Figure 2 This application can provide a puncture-resistant layer 11 on one side of the inner surface of the cover 201. The puncture-resistant layer 11 can play a blocking role, thereby improving the puncture resistance of the battery cover and protecting the battery.

[0108] In this example, the specific puncture strength of the puncture-resistant layer is greater than or equal to 1.0 N / μm. Specific puncture strength can be understood as the ability to withstand puncture force during a puncture test per unit thickness, expressed in N / μm. It is defined as the peak puncture force (N) during the puncture test (e.g., according to GB / T10004-2008) divided by the thickness (μm) of the test sample at the puncture site.

[0109] The puncture-resistant layer provided in this application has a high specific puncture strength, such as greater than or equal to 1.0 N / μm. Compared with some epoxy fiberglass battery covers, which have a specific puncture strength of 0.1 N / μm to 0.2 N / μm, the specific puncture strength of this application is significantly improved, thereby enhancing the strength of the battery cover and improving its puncture resistance.

[0110] In some examples, the specific puncture strength of the puncture-resistant layer is greater than or equal to 1.0 N / μm and less than or equal to 1.3 N / μm. For example, the specific puncture strength of the puncture-resistant layer is equal to 1.2 N / μm; another example is that the specific puncture strength of the puncture-resistant layer is equal to 1.1 N / μm.

[0111] In some examples, the density of the puncture-resistant layer material is less than or equal to 1.2 g / cm³. 3 .

[0112] For example, the density of the puncture-resistant layer material is less than or equal to 1.2 g / cm³. 3 ≥0.9g / cm 3 For example, the density of the puncture-resistant layer material is 1.1 g / cm³. 3 Alternatively, the density of the puncture-resistant layer material is equal to 1.0 g / cm³. 3 .

[0113] By using a puncture-resistant layer with a lower density, the weight of the puncture-resistant layer can be reduced, thereby reducing the weight of the battery cover and making the battery cover both high-strength and lightweight.

[0114] Among the available materials, the puncture-resistant layer 11 can be made of biaxially oriented ultra-high molecular weight polyethylene. "Biaxial orientation" refers to the tendency of the polymer's orientation units to align parallel to the plane of the external field under the influence of two mutually perpendicular external fields, while remaining randomly arranged within the plane.

[0115] Ultra-high molecular weight polyethylene (UHMWPE) can be understood as unbranched linear polyethylene with a molecular weight of over 1.5 million.

[0116] Biaxially oriented ultra-high molecular weight polyethylene has a puncture strength greater than or equal to 1.0 N / μm and a density less than or equal to 1.2 g / cm³. 3 The tensile strength can be greater than or equal to 350 MPa; therefore, by using biaxially oriented ultra-high molecular weight polyethylene as the puncture-resistant layer, the battery cover can meet the characteristics of high strength and ultra-thinness, and improve the puncture resistance of the battery cover.

[0117] In some examples, the thickness of the puncture-resistant layer 11 can be less than or equal to 150 μm. For example, it can be greater than or equal to 50 μm and less than or equal to 100 μm. Figure 2 In the example, the thickness of the puncture-resistant layer 11 can be 150 μm, 120 μm, 100 μm, 80 μm, or 50 μm.

[0118] Based on the above description, when using biaxially oriented ultra-high molecular weight polyethylene as the material of the puncture-resistant layer in this application, a single layer of biaxially oriented ultra-high molecular weight polyethylene film can not only achieve a specific puncture strength greater than or equal to 1.0 N / μm, but also a thickness of up to 150 μm. In other words, the range of thickness selection is wider, meaning that in this application, flexible selection of thickness and specific puncture strength can be taken into account at the same time.

[0119] On the other hand, because biaxially oriented ultra-high molecular weight polyethylene (UHMWPE) not only has high specific puncture strength, but its thickness can also be made thin or thick. This allows for the selection of different thicknesses of biaxially oriented UHMWPE film layers to meet varying puncture resistance requirements. For example, a single layer of biaxially oriented UHMWPE film can achieve the desired high puncture resistance.

[0120] However, in some related technologies, it is difficult to simultaneously achieve both high specific puncture strength and sufficient thickness in the puncture-resistant layer. For example, polyester film can be used as the puncture-resistant structure. Although the preferred puncture strength of polyester film can reach 1.0 N / μm, due to the processing characteristics of these materials, the puncture resistance cannot be linearly increased by adding a layer of film thickness. For instance, the thickness of a single film layer is generally less than 25 μm. If the thickness of a single film layer is greater than 25 μm, the specific puncture strength will be weakened. Therefore, if a puncture resistance of 100 N is required, at least six layers of polyester film, each 25 μm thick, are needed. This is because during hot-pressing lamination of six polyester films, the melting temperature of the polyester will disrupt the in-plane orientation of the individual film layers, thereby reducing the specific puncture strength. If the six polyester film layers are connected by an adhesive layer, the adhesive layer will also weaken the puncture resistance. Therefore, the total thickness of the puncture-resistant layer is greater than 150 μm. However, when the biaxially oriented ultra-high molecular weight polyethylene (UHMWPE) provided in this application is used as the material of the puncture-resistant layer, based on the characteristics of the biaxially oriented UHMWPE, the thickness of a single film layer can reach 150 μm. Thus, a film layer with a thickness of 100 μm can be used to achieve a puncture resistance of 100 N. Compared with 150 μm, 100 μm can significantly reduce the thickness of the puncture-resistant layer.

[0121] In other related technologies, fibrous fabrics can be used as puncture-resistant layers. The minimum thickness of these fabrics is limited by the diameter of the individual filaments. Typical organic fiber filaments have a diameter exceeding 17 μm, and fibrous fabrics are woven from bundles of these filaments. To achieve a puncture resistance of 100 N, the fabric thickness typically needs to exceed 200 μm. However, using the biaxially oriented ultra-high molecular weight polyethylene of this application, with a puncture strength greater than or equal to 1.0 N / μm, the thickness only needs to be 100 μm. This significantly reduces the thickness of the puncture-resistant layer, and consequently, the thickness of the cap. (Continued...) Figure 2 As shown, it may also include a first buffer layer 21 and a second buffer layer 22, with an anti-puncture layer 11 disposed between the first buffer layer 21 and the second buffer layer 22, that is, the anti-puncture layer 11 is sandwiched between the two buffer layers that serve as a carrier. The first buffer layer 21 is bonded to the inner surface of the cover 201 by an adhesive layer 31.

[0122] The buffer layer in this example serves a cushioning function, or even a protective function. Utilizing the cushioning effect of the buffer layer can further protect the battery and improve the performance of the puncture-resistant battery cover. For example, if an electronic device is dropped onto a sharp object, the cushioning effect of the buffer layer, combined with the barrier effect of the puncture-resistant layer, effectively protects the battery and reduces the likelihood of it being punctured.

[0123] Figure 3 This is a schematic diagram of the inner surface structure of the cover 201 in this application example. Figure 2 It can be along Figure 3 A sectional view of QQ section. Figure 3 The diagram illustrates the positional relationship between the first buffer layer 21 and the puncture-resistant layer 11. In some examples, Figure 2 The second buffer layer 22 in the middle can also be Figure 3 The structure of the first buffer layer 21 is shown.

[0124] like Figure 3 As shown, the orthographic projection of the puncture-resistant layer 11 onto the first buffer layer 21 is located within the boundary of the first buffer layer 21; or, the orthographic projection of the puncture-resistant layer 11 onto the second buffer layer 22 is located within the boundary of the second buffer layer 22.

[0125] The orthographic projection of the puncture-resistant layer 11 onto the first buffer layer 21 in this example can be understood as the vertical projection of the puncture-resistant layer 11 onto the first buffer layer 21 along the stacking direction of the first buffer layer and the puncture-resistant layer. The orthographic projection of the puncture-resistant layer 11 onto the second buffer layer 22 in this example can be understood as the vertical projection of the puncture-resistant layer 11 onto the second buffer layer 22 along the stacking direction of the second buffer layer and the puncture-resistant layer.

[0126] like Figure 3Since the area of ​​the first buffer layer 21 is larger than that of the puncture-resistant layer 11, a larger area adhesive layer 31 can be used to fix the puncture-resistant layer 11 to the cover 201, thereby improving the connection strength between the puncture-resistant layer 11 and the cover 201.

[0127] In some examples, the area of ​​the second buffer layer 22 is substantially the same as the area of ​​the first buffer layer 21. The puncture-resistant layer 11 is disposed between the first buffer layer 21 and the second buffer layer 22. For example, as... Figure 2 The first buffer layer 21 is connected to the second buffer layer 22 through the adhesive layer 32.

[0128] like Figure 3 and Figure 4 As shown, Figure 4 The structure of a first buffer layer 21 is shown. The first buffer layer 21 has a perforated structure 4 that extends through the first buffer layer 21 along its thickness direction. This reduces the weight of the first buffer layer, and consequently, the weight of the battery cover.

[0129] In some designs, to further reduce the weight of the battery cover, such as... Figure 2 The second buffer layer 22 can also have a hollow structure 4.

[0130] like Figure 3 and Figure 4 The hollow structure 4 can be multiple, and the multiple hollow structures 4 can be spaced apart along the outer periphery of the puncture-resistant layer 11.

[0131] This application does not limit the shape of the hollow structure 4; for example, it could be... Figure 3 and Figure 4 The structure shown can be a strip, or it can be a circular structure, or it can be any other shape.

[0132] Return to Figure 2 The first buffer layer 21 and the second buffer layer 22 in this application example can be made of various materials, such as at least one of foam, silicone, polyurethane, epoxy prepreg, or thermoplastic elastomer. For example, in Figure 2 In the example, the first or second buffer layer can be made of polyethylene terephthalate (PET) foam.

[0133] The materials of the first buffer layer 21 and the second buffer layer 22 can be the same or different.

[0134] The thickness of the first buffer layer 21 or the second buffer layer 22 can be from 0.1 mm to 0.4 mm. For example, the thickness of the first buffer layer 21 is 0.3 mm, and the thickness of the second buffer layer 22 can be 0.3 mm.

[0135] See Figure 2 The thickness of adhesive layer 31 or adhesive layer 32 can be from 10 μm to 40 μm. For example, the thickness of adhesive layer 31 is 15 μm and the thickness of adhesive layer 32 is 15 μm.

[0136] exist Figure 2 In the example, the thickness of the puncture-resistant layer 11 can be from 50 μm to 200 μm. For example, it can be 100 μm.

[0137] Figure 5 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes not only the cover body 201, adhesive layer 31, first buffer layer 21, puncture-resistant layer 11, second buffer layer 22 and adhesive layer 32, but may also include a third buffer layer 33 and puncture-resistant layer 12, with the puncture-resistant layer 12 stacked between the second buffer layer 22 and the third buffer layer 23.

[0138] The puncture-resistant layer 11 and the puncture-resistant layer 12 can be arranged relative to each other. This can be understood as follows: along the stacking direction of the puncture-resistant layer 12 and the puncture-resistant layer 11, the puncture-resistant layer 12 and the puncture-resistant layer 11 may partially overlap or completely overlap.

[0139] like Figure 5 The puncture-resistant layer 11 is closer to the cover 201 than the puncture-resistant layer 12. In some examples, the area of ​​the puncture-resistant layer 11 may be larger than the area of ​​the puncture-resistant layer 12.

[0140] In some structures, the thicknesses of the puncture-resistant layer 11 and the puncture-resistant layer 12 may be equal, or the thickness of the puncture-resistant layer 11 may be greater than the thickness of the puncture-resistant layer 12. The thickness of either the puncture-resistant layer 11 or the puncture-resistant layer 12 may range from 50 μm to 200 μm. For example, it may be 50 μm.

[0141] In some examples, see Figure 5 The areas of the second buffer layer 22 and the third buffer layer 23 can be larger than the area of ​​the puncture-resistant layer 12. The second buffer layer 22 is connected to the third buffer layer 23 through an adhesive layer 33.

[0142] To reduce the weight of the battery cover, a perforated structure 4 can be provided on the third buffer layer 23.

[0143] exist Figure 5 In the example, the thickness of the adhesive layer can be from 10 μm to 40 μm. For example, it can be 10 μm.

[0144] The following uses Figure 6 This application describes a method for preparing an anti-puncture layer, in order to obtain... Figure 2 The structure shown is an example.

[0145] like Figure 6 A, a first buffer layer 21 and a second buffer layer 22 are obtained, wherein the surface of the first buffer layer 21 has an adhesive layer 31 and the surface of the second buffer layer 22 has an adhesive layer 32.

[0146] like Figure 6 B, the puncture-resistant layer 11 is sandwiched between the first buffer layer 21 and the second buffer layer 22, and the first buffer layer 21 and the second buffer layer 22 are connected by the adhesive layer 32.

[0147] like Figure 6 C, the stacked first buffer layer 21, second buffer layer 22 and puncture-resistant layer 11 are connected to the inner surface of the cover 201 by the adhesive layer 31.

[0148] use Figure 6 The method shown yields Figure 2 The structure shown is relatively simple to prepare, easy to implement, and has a low preparation cost.

[0149] In some structures, Figure 2 and Figure 5 The multi-layered stacked structure shown, disposed on one side of the inner surface of the cover 201, can be referred to as a protective film. This protective film includes at least two buffer layers, with a puncture-resistant layer between adjacent buffer layers. This protective film can be applied not only to battery covers but also to other structures, such as microwave antenna covers in wireless base stations, or the interlayer of catheters or infusion bags in medical devices.

[0150] Figure 7 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 may include a cover body 201 and a puncture-resistant layer 11, the puncture-resistant layer 11 being located within a buffer substrate 2, and the buffer substrate 2 being disposed on the inner surface of the cover body 201.

[0151] In this example, the buffer substrate 2 is used as the carrier of the puncture-resistant layer 11 to support the puncture-resistant layer 11. The buffer substrate 2 has a buffering effect, which further improves the puncture resistance.

[0152] Figure 7 In the example, the buffer substrate 2 is directly connected to the inner surface of the cover 201, which can reduce the overall thickness of the battery cover and further achieve a thinner and lighter design.

[0153] The buffer matrix 2 can be made of a variety of materials, such as polyurethane thermoplastic elastomer, ethylene-vinyl acetate copolymer thermoplastic elastomer, polyamide thermoplastic elastomer, or polystyrene thermoplastic elastomer, etc.

[0154] In this embodiment, the thickness of the buffer substrate 2 can be from 0.20 mm to 0.50 mm. For example, the thickness of the buffer substrate 2 is 0.30 mm; or, for another example, the thickness of the buffer substrate 2 is 0.25 mm.

[0155] like Figure 7 In the example, the puncture resistance layer 11 has a specific puncture strength greater than or equal to 1.0 N / μm and a density less than or equal to 1.2 g / cm³. 3 The tensile strength can be greater than or equal to 350 MPa. For example, biaxially oriented ultra-high molecular weight polyethylene can be selected, which allows the battery cover to meet the characteristics of high strength and ultra-thinness, and improves the puncture resistance of the battery cover.

[0156] exist Figure 7 In the example, the thickness of the puncture-resistant layer 112 can be from 50 μm to 200 μm. For example, it can be 100 μm.

[0157] Figure 8 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes a cover body 201, and has a puncture-resistant layer 11 and a puncture-resistant layer 12 on one side of the inner surface of the cover body 201. The puncture-resistant layer 11 and the puncture-resistant layer 12 are located inside the buffer substrate 2, and the buffer substrate 2 is disposed on the inner surface of the cover body 201.

[0158] The puncture-resistant layer 11 and the puncture-resistant layer 12 can be arranged relative to each other. For example, along the stacking direction of the puncture-resistant layer 12 and the puncture-resistant layer 11, the puncture-resistant layer 12 and the puncture-resistant layer 11 may partially overlap or completely overlap.

[0159] In some structures, the thicknesses of the puncture-resistant layer 11 and the puncture-resistant layer 12 may be equal, or the thickness of the puncture-resistant layer 11 may be greater than the thickness of the puncture-resistant layer 12. The thickness of either the puncture-resistant layer 11 or the puncture-resistant layer 12 may range from 50 μm to 200 μm. For example, it may be 50 μm.

[0160] The following uses Figure 9 This application describes a method for preparing an anti-puncture layer, in order to obtain... Figure 7 The structure shown is an example.

[0161] like Figure 9 A, to obtain a first buffer layer 21 and a second buffer layer 22. The first buffer layer 21 and the second buffer layer 22 can be selected from polyurethane-type thermoplastic elastomer materials.

[0162] like Figure 9 B, the puncture-resistant layer 11 is sandwiched between the first buffer layer 21 and the second buffer layer 22.

[0163] like Figure 9 C, the stacked first buffer layer 21, second buffer layer 22, and puncture-resistant layer 11 are subjected to heating and pressurization treatment, for example, at a temperature of 120°C to 140°C and a pressure of 5MPa to 50MPa, so that the first buffer layer 21 and the second buffer layer 22 are thermally melted to form a buffer substrate 2, which encapsulates the puncture-resistant layer 11. Furthermore, the buffer substrate 2 can be directly attached to the inner surface of the cover 201.

[0164] In order to improve the bonding strength between the buffer substrate 2 and the inner surface of the cover 201, the inner surface of the cover 201 can be surface treated before heating and pressurizing the first buffer layer 21 and the second buffer layer 22 to increase the surface energy and introduce polar groups to increase the surface affinity. For example, the inner surface of the cover 201 can be corona treatment or plasma treatment.

[0165] To prevent delamination between the puncture-resistant layer 11 and the buffer substrate 2, such as Figure 9 For option B, when selecting puncture-resistant layer 11, a puncture-resistant layer with porosity can be selected, for example, a puncture-resistant layer with a porosity of 10% to 30%, as shown in the example. Figure 9 If the porosity of the puncture-resistant layer in B is 20%, then when the first buffer layer 21, the second buffer layer 22 and the puncture-resistant layer 11 are heated and pressurized, the materials of the first buffer layer 21 and the second buffer layer 22 can partially penetrate into the puncture-resistant layer 11, thereby increasing the connection strength between the puncture-resistant layer 11 and the buffer substrate 2 and reducing the risk of delamination between the puncture-resistant layer 11 and the buffer substrate 2.

[0166] In some processes, when materials from the first buffer layer 21 and the second buffer layer 22 partially penetrate into the puncture-resistant layer 11, such as... Figure 10 The puncture-resistant layer 11 contains the material of the buffer matrix 2.

[0167] In the above examples, the puncture-resistant layer 11 is disposed on one side of the inner surface of the cover 201 of the battery cover, for example, by adhering to the inner surface of the cover 201 by an adhesive layer, or by directly attaching it to the inner surface of the cover 201.

[0168] In the examples above, the cover 201 can be made of a variety of materials, such as glass, resin, or other materials.

[0169] In some structures, Figure 7 and Figure 8The multi-layered stacked structure shown, disposed on one side of the inner surface of the cover 201, can also be referred to as a protective film. This protective film includes a buffer substrate, within which at least one puncture-resistant layer is disposed. This protective film can be applied not only to battery covers but also to other structures, such as microwave antenna covers in wireless base stations, or the interlayer of catheters or infusion bags in medical devices.

[0170] Figure 11 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes a cover body 201, which includes a resin matrix 201A. For example, the cover body 201 can be made of epoxy resin; the puncture-resistant layer 11 is disposed in the resin matrix 201A.

[0171] like Figure 11 In the example, the puncture resistance layer 11 has a specific puncture strength greater than or equal to 1.0 N / μm and a density less than or equal to 1.2 g / cm³. 3 The tensile strength can be greater than or equal to 350 MPa. For example, biaxially oriented ultra-high molecular weight polyethylene can be selected, which can make the battery cover meet the characteristics of high strength and ultra-thinness, and improve the puncture resistance of the battery cover.

[0172] exist Figure 11 In the example, the thickness of the puncture-resistant layer 11 can be from 50 μm to 200 μm. For example, it can be 100 μm.

[0173] Figure 12 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes a cover body 201, which includes a resin matrix 201A, and also includes an anti-puncture layer 11 and an anti-puncture layer 12, which are disposed in the resin matrix 201A.

[0174] The puncture-resistant layer 11 and the puncture-resistant layer 12 can be arranged relative to each other. For example, along the stacking direction of the puncture-resistant layer 12 and the puncture-resistant layer 11, the puncture-resistant layer 12 and the puncture-resistant layer 11 may partially overlap or completely overlap.

[0175] exist Figure 12 In the example, the thicknesses of the puncture-resistant layer 11 and the puncture-resistant layer 12 can be equal or unequal. For example, they can be from 50 μm to 200 μm. For instance, the thickness of the puncture-resistant layer 11 and the puncture-resistant layer 12 can be 50 μm.

[0176] exist Figure 11 and Figure 12 In the example, the puncture-resistant layer 11 is disposed inside the cover 201, which allows for a further reduction in the thickness of the battery cover.

[0177] The following uses Figure 13 This application describes a method for preparing an anti-puncture layer, in order to obtain... Figure 11 The structure shown is an example.

[0178] like Figure 13 A first buffer layer 21 and a second buffer layer 22, as well as a puncture-resistant layer 11, are obtained, and the puncture-resistant layer 11 is sandwiched between the first buffer layer 21 and the second buffer layer 22. The first buffer layer 21 and the second buffer layer 22 can be made of the same material as the cover 201; for example, if the cover 201 is made of epoxy resin, both the first buffer layer 21 and the second buffer layer 22 can be made of epoxy resin.

[0179] For example, the thickness of the first buffer layer 21 and the second buffer layer 22 can be from 0.1 mm to 0.4 mm. For instance, it can be 0.2 mm.

[0180] like Figure 13 B, for Figure 13 The structure shown in A is subjected to heating and pressurization treatment, which causes the first buffer layer 21 and the second buffer layer 22 to melt together to form a buffer matrix 2, which encapsulates the puncture-resistant layer 11.

[0181] like Figure 13 C, prepare the cover 201, in the process of preparing the cover 201, Figure 13 The structure shown in B is placed in mold 5 for preparing the cover.

[0182] like Figure 13 Under heating and pressurizing conditions, the buffer matrix 2 can be fused with the material used to prepare the cover 201, and the puncture-resistant layer 11 is encapsulated within the fused resin matrix 201A, thereby producing a product as shown in Figure D. Figure 13 The battery cover structure shown in D.

[0183] Figure 13 The first buffer layer 21 and the second buffer layer 22 in A can be made of epoxy prepreg. The material used to prepare the cover 201 is also epoxy prepreg. This epoxy prepreg is compatible with the epoxy resin battery cover molding process when heated and pressurized at 120°C. This will not pose a challenge to the process or increase the manufacturing cost.

[0184] exist Figure 11 or Figure 12 In order to prevent the puncture-resistant layer 11 from delaminating from the resin matrix, such as Figure 13 In option A, when selecting the puncture-resistant layer 11, a puncture-resistant layer with porosity can be selected. For example, a puncture-resistant layer with a porosity of 10% to 30% can be selected. Figure 13If the porosity of the puncture-resistant layer in A is 20%, then during the preparation of the cover 201, the first buffer layer 21, the second buffer layer 22, or the material used to prepare the cover 201 can partially penetrate into the puncture-resistant layer 11 to improve the bonding strength between the puncture-resistant layer 11 and the resin matrix, reducing the risk of delamination between the puncture-resistant layer 11 and the resin matrix. For example, epoxy prepreg can penetrate into the puncture-resistant layer 11 during the secondary curing process, so that the final puncture-resistant layer contains epoxy prepreg.

[0185] In some processes, when the material of the resin matrix partially penetrates into the puncture-resistant layer 11, the puncture-resistant layer 11 of the resulting battery cover contains the material of the resin matrix.

[0186] Figure 14 This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes a cover body 201, the cover body 201 includes a resin matrix 201A, the resin matrix 201A has a buffer matrix 2, the material of the buffer matrix 2 is different from the material of the resin matrix 201A, and the buffer matrix 2 has a puncture-resistant layer 11.

[0187] Figure 14 In the example shown, it can be understood that the puncture-resistant layer 11 is wrapped inside the buffer matrix 2, and the buffer matrix 2 is wrapped inside the resin matrix 201A.

[0188] In some examples, the resin matrix 201A of the cover 201 can be made of epoxy resin, and the buffer matrix 2 can be made of at least one of the following materials: vinyl resin, unsaturated polyester resin, and polyurethane resin.

[0189] like Figure 14 In the example, the puncture resistance layer 11 has a specific puncture strength greater than or equal to 1.0 N / μm and a density less than or equal to 1.2 g / cm³. 3 The tensile strength can be greater than or equal to 350 MPa. For example, biaxially oriented ultra-high molecular weight polyethylene can be selected, which can make the battery cover meet the characteristics of high strength and ultra-thinness, and improve the puncture resistance of the battery cover.

[0190] exist Figure 14 In the example, the thickness of the puncture-resistant layer 11 can be from 50 μm to 200 μm. For example, it can be 100 μm.

[0191] See Figure 14 The puncture-resistant layer 11 is embedded in the cover 201, which reduces the thickness of the battery cover.

[0192] Figure 15This is a schematic diagram of another battery cover 200 provided in the embodiments of this application. In this example, the battery cover 200 includes a cover body 201, the cover body 201 includes a resin matrix 201A, the resin matrix 201A has a buffer matrix 2, the buffer matrix 2 has a puncture-resistant layer 11 and a puncture-resistant layer 12, and the puncture-resistant layer 11 and the puncture-resistant layer 12 can be disposed opposite to each other in the buffer matrix 2.

[0193] The thickness of the puncture-resistant layer 11 or the thickness of the puncture-resistant layer 12 can be from 50 μm to 200 μm. For example, the thickness of the puncture-resistant layer 11 or the thickness of the puncture-resistant layer 12 can both be 50 μm.

[0194] The following uses Figure 16 This application describes a method for preparing an anti-puncture layer, in order to obtain... Figure 14 The structure shown is an example.

[0195] like Figure 16 A first buffer layer 21 and a second buffer layer 22, and a puncture-resistant layer 11 are obtained, with the puncture-resistant layer 11 sandwiched between the first buffer layer 21 and the second buffer layer 22. The first buffer layer 21 and the second buffer layer 22 may be made of materials different from the cover 201; for example, the cover 201 may be made of epoxy resin, while the first buffer layer 21 and the second buffer layer 22 may be made of vinyl resin.

[0196] like Figure 16 B, for Figure 16 The structure shown in A is subjected to heating and pressurization treatment, which causes the first buffer layer 21 and the second buffer layer 22 to melt together to form a buffer matrix 2, which encapsulates the puncture-resistant layer 11.

[0197] like Figure 16 C, prepare the cover 201, in the process of preparing the cover 201, Figure 16 The structure shown in B is placed in mold 5 for preparing the cover.

[0198] like Figure 16 Under heating and pressurizing conditions, resin matrix 201A encapsulates buffer matrix 2, thereby producing a product as shown in Figure D. Figure 16 The battery cover structure shown in D.

[0199] Figure 11 and Figure 12 ,as well as Figure 14 and Figure 15 In one configuration, the puncture-resistant layer 11 is embedded within the cover of the battery cover. In other configurations, the puncture-resistant layer 11 can be embedded within other cover structures, such as in a battery pack protective cover or a waterproof liquid-repellent cover for a medical device.

[0200] In some of the examples shown above, the puncture-resistant layer is disposed on one side of the inner surface of the cover, and such a structure can be called an attached puncture-resistant structure; in other embodiments, the puncture-resistant layer is disposed inside the cover, and such a structure can be called an embedded puncture-resistant structure.

[0201] The following also provides some example battery cover structures, such as... Figure 17 and Figure 18 As shown, it includes a puncture-resistant layer 11 and a puncture-resistant layer 13, wherein the puncture-resistant layer 11 is disposed on one side of the inner surface of the cover 201, and the puncture-resistant layer 13 is disposed inside the cover 201.

[0202] See Figure 17 and Figure 18 The puncture-resistant layer 11 and the puncture-resistant layer 13 can be arranged relative to each other. Figure 17 In the middle, the puncture-resistant layer 11 and the puncture-resistant layer 13 are basically completely aligned; in Figure 18 In the middle, the puncture-resistant layer 11 and the puncture-resistant layer 13 partially overlap.

[0203] In order to effectively protect battery 400, such as Figure 19 The puncture-resistant layer 11 or puncture-resistant layer 13 may be opposite to the central region of the battery.

[0204] See Figure 20 When the puncture-resistant layer 11 and the puncture-resistant layer 13 partially overlap, the overlapping area of ​​the puncture-resistant layer 11 and the puncture-resistant layer 13 can be opposite to the central area of ​​the battery 400, so that the central area of ​​the battery is effectively protected.

[0205] The non-overlapping areas of the puncture-resistant layer 11 and the puncture-resistant layer 13 can cover other areas of the battery, thus effectively protecting other areas of the battery 400.

[0206] In other examples, multiple puncture-resistant layers can be provided, with some layers disposed on the inner surface of the cover 201 and others embedded in the resin matrix of the cover 201. These multiple puncture-resistant layers have overlapping areas, which overlap with the central region of the battery.

[0207] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0208] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery cover, characterized in that, include: Cover; A puncture-resistant layer is disposed on the side of the cover near the battery, and / or the cover includes a resin matrix in which the puncture-resistant layer is disposed; The puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture resistance layer comprises biaxially oriented ultra-high molecular weight polyethylene.

2. The battery cover according to claim 1, characterized in that, The thickness of the puncture-resistant layer is less than or equal to 150 μm.

3. The battery cover according to claim 1 or 2, characterized in that, The tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the material of the puncture-resistant layer is less than or equal to 1.2 g / cm³. 3 .

4. The battery cover according to any one of claims 1-3, characterized in that, When the puncture-resistant layer is disposed on the side of the cover near the battery, The battery cover further includes: a first buffer layer and a second buffer layer; The puncture-resistant layer is disposed between the first buffer layer and the second buffer layer; The first buffer layer is disposed on the surface of the cover near the battery via an adhesive layer.

5. The battery cover according to claim 4, characterized in that, The orthographic projection of the puncture-resistant layer onto the first buffer layer is located within the boundary of the first buffer layer; the orthographic projection of the puncture-resistant layer onto the second buffer layer is located within the boundary of the second buffer layer; The first buffer layer is connected to the second buffer layer through an adhesive layer.

6. The battery cover according to claim 4 or 5, characterized in that, The portion of the first buffer layer that does not overlap with the puncture-resistant layer has a perforated structure, and / or; The portion of the second buffer layer that does not overlap with the puncture-resistant layer has a hollow structure.

7. The battery cover according to any one of claims 1-3, characterized in that, When the puncture-resistant layer is disposed on the side of the cover near the battery, The battery cover also includes: a buffer base; The puncture-resistant layer is disposed in the buffer matrix; The buffer substrate is disposed on the surface of the cover near the battery.

8. The battery cover according to claim 7, characterized in that, The puncture-resistant layer contains the material of the buffer matrix.

9. The battery cover according to any one of claims 1-8, characterized in that, When the puncture-resistant layer is disposed in the resin matrix, the puncture-resistant layer contains the material of the resin matrix.

10. The battery cover according to any one of claims 1-8, characterized in that, When the puncture-resistant layer is disposed in the resin matrix, the resin matrix has a buffer matrix, and the material of the resin matrix and the material of the buffer matrix are different; The puncture-resistant layer is located within the buffer matrix, and the puncture-resistant layer contains the material of the buffer matrix.

11. An electronic device, characterized in that, include: Battery; The battery cover as described in any one of claims 1-10, wherein the battery cover is disposed on one side of the battery; The puncture-resistant layer's orthogonal projection onto the battery at least partially overlaps with the battery.

12. A protective film, characterized in that, include: Buffer structure; A puncture-resistant layer, which is in contact with the buffer structure; The puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture resistance layer comprises biaxially oriented ultra-high molecular weight polyethylene.

13. The protective film according to claim 12, characterized in that, The thickness of the puncture-resistant layer is less than or equal to 150 μm.

14. The protective film according to claim 12 or 13, characterized in that, The tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the material of the puncture-resistant layer is less than or equal to 1.2 g / cm³. 3 .

15. The protective film according to any one of claims 12-14, characterized in that, The buffer structure includes: a first buffer layer and a second buffer layer, wherein the puncture-resistant layer is disposed between the first buffer layer and the second buffer layer, or... The buffer structure includes a buffer matrix, and the puncture-resistant layer is disposed in the buffer matrix, wherein the puncture-resistant layer contains the material of the buffer matrix.

16. A method for preparing a protective film, characterized in that, The preparation method includes: The puncture-resistant layer is placed between the first buffer layer and the second buffer layer; An adhesive layer is used to connect the first buffer layer and the second buffer layer, or the stacked first buffer layer, the puncture-resistant layer and the second buffer layer are subjected to heating and pressurization treatment, so that the first buffer layer and the second buffer layer are thermally melted to form a buffer matrix, and the buffer matrix wraps the puncture-resistant layer; The puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture resistance layer comprises biaxially oriented ultra-high molecular weight polyethylene.

17. The method for preparing the protective film according to claim 16, characterized in that, The porosity of the puncture-resistant layer is less than or equal to 30%.

18. A cover structure, characterized in that, include: Resin matrix; A puncture-resistant layer is disposed in the resin matrix; The puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture resistance layer comprises biaxially oriented ultra-high molecular weight polyethylene.

19. The cover structure according to claim 18, characterized in that, The thickness of the puncture-resistant layer is less than or equal to 150 μm.

20. The cover structure according to claim 18 or 19, characterized in that, The tensile strength of the puncture-resistant layer is greater than or equal to 350 MPa, and / or the density of the material of the puncture-resistant layer is less than or equal to 1.2 g / cm³. 3 .

21. The cover structure according to any one of claims 18-20, characterized in that, The puncture-resistant layer contains a material comprising the resin matrix, or, The resin matrix contains a buffer matrix, and the material of the resin matrix is ​​different from the material of the buffer matrix; The puncture-resistant layer is located within the buffer matrix, and the puncture-resistant layer contains the material of the buffer matrix.

22. A method for preparing a cover structure, characterized in that, The preparation method includes: The puncture-resistant layer is placed between the first buffer layer and the second buffer layer; The stacked first buffer layer, the puncture-resistant layer, and the second buffer layer are subjected to heating and pressurization treatment, causing the first buffer layer and the second buffer layer to melt and form a buffer matrix, which encapsulates the puncture-resistant layer; The structure comprising the puncture-resistant layer and the buffer matrix is ​​placed in a mold, and resin material is injected into the mold to form a resin matrix, such that the resin matrix encapsulates the buffer matrix and the puncture-resistant layer. The puncture resistance layer has a specific puncture strength greater than or equal to 1.0 N / μm, and the puncture resistance layer comprises biaxially oriented ultra-high molecular weight polyethylene.

23. The method for preparing the cover structure according to claim 22, characterized in that, The porosity of the puncture-resistant layer is less than or equal to 30%.

24. The method for preparing the cover structure according to claim 22 or 23, characterized in that, Both the first buffer layer and the second buffer layer are made of resin.

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