Flexible battery heating film and preparation process thereof

Abstract

The application discloses a flexible battery heating film and a preparation process thereof, which comprises a first insulating layer, a first heat-conducting adhesive layer, a heating layer, a second heat-conducting adhesive layer and a second insulating layer from bottom to top; the heating layer comprises an electrode part and a heating part, and the heating part is wrapped by the first heat-conducting adhesive layer and the second heat-conducting adhesive layer; the preparation process comprises the following steps: coating the first heat-conducting adhesive layer on a first surface of a copper foil, and hot-pressing the first insulating layer on the first heat-conducting adhesive layer; preparing the heating layer composed of the electrode part and the heating part on a second surface of the copper foil through an etching process; coating the second heat-conducting adhesive layer on the heating layer, and hot-pressing the second insulating layer on the second heat-conducting adhesive layer; and the beneficial effect is that the first heat-conducting adhesive layer and the second heat-conducting adhesive layer are arranged on two surfaces of the heating layer respectively, so that the heat of the heating layer is fully dispersed to uniformly heat the battery, heat concentration is prevented to avoid ablation of the insulating layer, and the safety performance of the flexible battery heating film is improved.

Description

Technical Field

[0001] This invention relates to the field of battery heating materials technology, and in particular to a flexible battery heating film and its preparation process. Background Technology

[0002] With the increasing popularity of battery-powered new energy vehicles, a significant decrease in driving range occurs in low-temperature environments. To mitigate this range reduction, insulation and heating methods are used to raise the battery's operating temperature. Currently, battery heating primarily employs flexible heating pads to heat the battery's outer surface. These pads consist of a patterned heating layer between two insulating layers. However, after prolonged and repeated heating, the heat concentrates primarily on the heating conductors and their surroundings. Since the insulation layer's heat dissipation capacity is weaker than the conductors, uneven surface temperature occurs on the heating pad. Excessive heat concentration on the conductors and their surroundings causes the insulation layer connected to the conductors to blacken or even burn. Burning exposes the conductors, posing a significant safety hazard to the battery.

[0003] Therefore, it is necessary to improve and optimize the existing flexible battery heating film and its preparation process to address the aforementioned technical deficiencies. Summary of the Invention

[0004] The purpose of this invention is to disclose a flexible battery heating film and its preparation process. By setting a first thermally conductive adhesive layer and a second thermally conductive adhesive layer on two sides of the heating layer, the heat of the heating layer is fully dispersed, preventing heat concentration and erosion of the insulating layer.

[0005] The first objective of this invention is to provide a flexible battery heating film.

[0006] The second objective of this invention is to provide a process for preparing a flexible battery heating film.

[0007] To achieve the first objective mentioned above, the present invention provides a flexible battery heating film, which, from bottom to top, comprises a first insulating layer, a first thermally conductive adhesive layer, a heating layer, a second thermally conductive adhesive layer, and a second insulating layer; the heating layer includes an electrode portion and a heating portion, and the heating portion is wrapped by the first thermally conductive adhesive layer and the second thermally conductive adhesive layer.

[0008] Preferably, a hollow portion is provided in the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion corresponds to the position of the hollow portion.

[0009] Preferably, the thickness of the first insulating layer is 30μm-60μm, the thickness of the first thermally conductive adhesive layer is 10μm-50μm, the thickness of the heating layer is 30μm-60μm, the thickness of the second thermally conductive adhesive layer is 10μm-50μm, and the thickness of the second insulating layer is 30μm-60μm.

[0010] Preferably, the heating element has a uniformly distributed pattern.

[0011] Based on the same inventive principle, in order to achieve the second inventive objective mentioned above, this invention provides a process for preparing a flexible battery heating film, comprising the following steps:

[0012] A first thermally conductive adhesive layer is coated on the first surface of the copper foil, and a first insulating layer is hot-pressed onto the first thermally conductive adhesive layer.

[0013] A heating layer consisting of an electrode portion and a heating portion is prepared on the second surface of the copper foil by an etching process;

[0014] A second thermally conductive adhesive layer is applied to the heating layer, and a second insulating layer is hot-pressed onto the second thermally conductive adhesive layer.

[0015] Based on the same inventive principle, in order to achieve the second inventive objective mentioned above, the present invention also provides a process for preparing a flexible battery heating film, comprising the following steps:

[0016] A first thermally conductive adhesive layer is coated on the surface of the first insulating layer, and the first surface of the copper foil is hot-pressed onto the first thermally conductive adhesive layer.

[0017] A heating layer consisting of an electrode portion and a heating portion is prepared on the second surface of the copper foil by an etching process;

[0018] A second thermally conductive adhesive layer is applied to the heating layer, and a second insulating layer is hot-pressed onto the second thermally conductive adhesive layer.

[0019] Preferably, the method further includes the following step: using a laser to ablate a hollow portion in the second insulating layer and the second thermally conductive adhesive layer, wherein the electrode portion corresponds to the position of the hollow portion.

[0020] Preferably, the thickness of the first insulating layer is 30μm-60μm, the thickness of the first thermally conductive adhesive layer is 10μm-50μm, the thickness of the heating layer is 30μm-60μm, the thickness of the second thermally conductive adhesive layer is 10μm-50μm, and the thickness of the second insulating layer is 30μm-60μm.

[0021] Preferably, the heating element has a uniformly distributed pattern.

[0022] Preferably, the pattern is wavy.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] By setting a first thermally conductive adhesive layer and a second thermally conductive adhesive layer on two sides of the heating layer, the heat of the heating layer is fully dispersed and the battery is heated evenly, preventing heat concentration and burning of the insulation layer, thus increasing the safety performance of the flexible battery heating film. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of the flexible battery heating film of the present invention.

[0026] Figure 2 This is a top view schematic diagram of the flexible battery heating film of the present invention.

[0027] Figure 3 This is a schematic cross-sectional view of the existing flexible battery heating film of the present invention.

[0028] Figure 4 This is a flowchart of the process for preparing the flexible battery heating film according to Embodiment 2 of the present invention.

[0029] Figure 5 This is a flowchart of the process for preparing the flexible battery heating film according to Embodiment 3 of the present invention.

[0030] Among them, 1. First insulating layer; 2. First thermally conductive adhesive layer; 3. Heating layer; 31. Electrode part; 32. Heating part; 321. Straight copper foil; 322. Wavy copper foil; 323. Heating blank area; 4. Second thermally conductive adhesive layer; 5. Second insulating layer; 6. Hollowed-out part. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0033] The specific implementation process of the present invention will be described below through several embodiments.

[0034] Example 1:

[0035] like Figure 1 and Figure 2 As shown, this embodiment provides a flexible battery heating film, which includes, from bottom to top, a first insulating layer 1, a first thermally conductive adhesive layer 2, a heating layer 3, a second thermally conductive adhesive layer 4, and a second insulating layer 5; the heating layer 3 includes an electrode portion 31 and a heating portion 32, and the heating portion 32 is wrapped by the first thermally conductive adhesive layer 2 and the second thermally conductive adhesive layer 3.

[0036] Specifically, the first insulating layer 1 and the second insulating layer 5 are made of PI film with a thickness of 30μm-60μm, preferably 50μm; the first thermally conductive adhesive layer 2 and the second thermally conductive adhesive layer 4 both have a thickness of 10μm-50μm, preferably 30μm; the heating layer 3 is preferably a perforated brass foil with a thickness of 30μm-60μm, preferably 50μm; perforated portions 6 are provided in the second insulating layer 5 and the second thermally conductive adhesive layer 4, and the electrode portion 31 corresponds to the position of the perforated portion 6. See [reference needed]. Figure 1 The heating layer 3 includes an electrode portion 31 and a heating portion 32, wherein, at a position corresponding to the electrode portion 31, i.e. Figure 2 The area within the dashed box shown has a cutout portion 6, which is formed by laser ablation of the second insulating layer 5 and the second thermally conductive adhesive layer 4. The electrode portion 31 is connected to an external power source through the cutout portion 6. When powered on, the heating portion 32 provides a heat source for the battery. The heating portion 32 has a uniformly distributed pattern, for example, see [reference needed]. Figure 2 The heating part 32 includes a straight copper foil 321 and a wavy copper foil 322. The wavy copper foil 322 is evenly distributed on the heating film. The straight copper foil 321 and the wavy copper foil 322 form a heating area, and the area without copper foil is a heating blank area 323.

[0037] See Figure 3 The existing heating element 32 also has a heating area and a heating blank area, but the heating area is directly sandwiched between the first and second insulating layers. The heat of the heating element 32 is concentrated in the heating area, that is, the contact area between the heating element 32 and the insulating layer. Due to the poor heat dissipation performance of the insulating layer, the heat in the heating area cannot be diffused to the heating blank area 323 in time, causing the heat of the insulating layer in direct contact with the heating element 32 to concentrate, making the insulating layer in the heating area more prone to blackening or even burning, thus affecting the safety of the battery. Unlike the prior art, the heating layer 3 is wrapped by the first thermally conductive adhesive layer 2 and the second thermally conductive adhesive layer 3, see [link to previous text]. Figure 1Not only is the heating zone formed by the straight copper foil 321 and the wavy copper foil 322 sandwiched between the first thermally conductive adhesive layer 2 and the second thermally conductive adhesive layer 3, but the heating blank area 323 is also filled with thermally conductive adhesive, so that the heat of the heating layer 3 is effectively dispersed instead of concentrated in the heating zone, thereby effectively reducing the phenomenon of the first insulating layer 1 and the second insulating layer 5 being burned or even eroded, making the battery operation safer.

[0038] Example 2:

[0039] See Figure 4 This embodiment provides a process for preparing a flexible battery heating film, including the following steps:

[0040] Step S1: Coat the first thermally conductive adhesive layer 2 on the first surface of the copper foil, and hot-press the first insulating layer 1 onto the first thermally conductive adhesive layer 2; the copper foil is preferably made of brass, and the thickness of the copper foil is 30μm-60μm, preferably 50μm. The first thermally conductive adhesive layer 2 with a thickness of 10μm-50μm is bonded to the first surface of the copper foil by a coating process; the first insulating layer 1 is made of PI film and has a thickness of 30μm-60μm, preferably 50μm.

[0041] Step S2: A heating layer 3, consisting of an electrode portion 31 and a heating portion 32, is prepared on the second surface of the copper foil by an etching process. Specifically, the electrode portion 31 and the heating portion 32 are prepared on the second surface of the copper foil, i.e., the exposed surface, by an etching process. The electrode portion 31 is used to connect to an external power source, and when energized, the heating portion 32 provides a heat source for the battery through its heating. The heating portion 32 has a uniformly distributed pattern, preferably a wavy pattern, for example, see [reference needed]. Figure 2 The heating part 32 includes a straight copper foil 321 and a wavy copper foil 322. The wavy copper foil 322 is evenly distributed on the heating film. The straight copper foil 321 and the wavy copper foil 322 form a heating area. The area without copper foil is a heating blank area 323, which is the area where the copper foil has been etched away.

[0042] Step S3: A second thermally conductive adhesive layer 4 is applied to the heating layer 3, and a second insulating layer 5 is hot-pressed onto the second thermally conductive adhesive layer 4. Specifically, when applying the second thermally conductive adhesive layer 4, the adhesive not only adheres to the surfaces of the straight copper foil 321 and the wavy copper foil 322, but also fills the heating blank area 323, so that all surfaces of the heating part 32 are covered, thereby diffusing the heat of the heating part 32 to the heating blank area 323, effectively avoiding heat concentration in the heating part 32, and solving the defect of blackening or even burning of the insulating layer caused by heat concentration in the existing heating part; the thickness of the second thermally conductive adhesive layer 4 is 10μm-50μm, preferably 30μm, and the second insulating layer 5 is made of PI film with a thickness of 30μm-60μm, preferably 50μm.

[0043] After completing step S3, the electrode portion 31 is shielded by the second thermally conductive adhesive layer 4 and the second insulating layer 5. Before installing the flexible battery heating film onto the battery, a laser is needed to ablate the second insulating layer 5 and the second thermally conductive adhesive layer 4 to create a perforated portion 6. The electrode portion 31 corresponds to the perforated portion 6. The position of the perforated portion 6 is shown in [reference needed]. Figure 2 At the location indicated by the dashed box, the electrode part 31 is connected to an external power source through the cutout part 6.

[0044] The flexible battery heating film preparation process disclosed in this embodiment has the same technical solution as that in Embodiment 1. Please refer to Embodiment 1 for details, which will not be repeated here.

[0045] Example 3:

[0046] The difference from Embodiment 2 is that, unlike step S1 in Embodiment 2, Embodiment 3 uses step A1 instead of S1. Step A1: A first thermally conductive adhesive layer 2 is coated on the surface of the first insulating layer 1, and the first surface of the copper foil is hot-pressed onto the first thermally conductive adhesive layer 2. Specifically, the copper foil is preferably made of brass and has a thickness of 30μm-60μm, preferably 50μm. The first thermally conductive adhesive layer 2 with a thickness of 10μm-50μm is coated onto the surface of the first insulating layer 1 through a coating process. The first insulating layer 1 is made of PI film and has a thickness of 30μm-60μm, preferably 50μm. Then the copper foil is hot-pressed onto the first insulating layer 1.

[0047] Step A2 in Example 3 is the same as step S2 in Example 2, and will not be repeated here.

[0048] Step A3 in Example 3 is the same as step S3 in Example 2, and will not be repeated here.

[0049] The flexible battery heating film preparation process disclosed in this embodiment has the same technical solution as that in Embodiment 2. Please refer to Embodiment 2 for details, which will not be repeated here.

Claims

1. A flexible battery heating film, characterized in that, From bottom to top, it includes a first insulating layer with a thickness of 30μm-60μm, a first thermally conductive adhesive layer with a thickness of 10μm-50μm, a heating layer with a thickness of 30μm-60μm, a second thermally conductive adhesive layer with a thickness of 10μm-50μm, and a second insulating layer with a thickness of 30μm-60μm. The heating layer includes an electrode part and a heating part. The heating part is wrapped by the first thermally conductive adhesive layer and the second thermally conductive adhesive layer. All sides of the heating part are wrapped. The heating section includes straight copper foil and wavy copper foil. The wavy copper foil is evenly distributed on the heating film. The straight copper foil and the wavy copper foil form the heating zone, and the area without copper foil is the heating blank zone. The heating blank area is filled with thermally conductive adhesive, and the heat from the heating part diffuses to the heating blank area; a hollow part is provided in the second insulating layer and the second thermally conductive adhesive layer, and the electrode part is positioned corresponding to the hollow part; The flexible battery heating film is prepared through the following steps. A first thermally conductive adhesive layer is coated on the first surface of the copper foil, and a first insulating layer is hot-pressed onto the first thermally conductive adhesive layer. A heating layer consisting of an electrode portion and a heating portion is prepared on the second surface of the copper foil by an etching process; A second thermally conductive adhesive layer is applied to the heating layer, and a second insulating layer is hot-pressed onto the second thermally conductive adhesive layer. A hollowed-out portion is created by laser ablation of the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion is positioned corresponding to the hollowed-out portion.

2. A flexible battery heating film, characterized in that, From bottom to top, it includes a first insulating layer with a thickness of 30μm-60μm, a first thermally conductive adhesive layer with a thickness of 10μm-50μm, a heating layer with a thickness of 30μm-60μm, a second thermally conductive adhesive layer with a thickness of 10μm-50μm, and a second insulating layer with a thickness of 30μm-60μm. The heating layer includes an electrode portion and a heating portion, and the heating portion is wrapped by the first thermally conductive adhesive layer and the second thermally conductive adhesive layer; The heating section includes straight copper foil and wavy copper foil. The wavy copper foil is evenly distributed on the heating film. The straight copper foil and the wavy copper foil form the heating zone, and the area without copper foil is the heating blank zone. The heating blank area is filled with thermally conductive adhesive, and the heat from the heating part diffuses to the heating blank area; A cutout portion is provided in the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion is positioned corresponding to the cutout portion; The flexible battery heating film is prepared through the following steps. A first thermally conductive adhesive layer is coated on the surface of the first insulating layer, and the first surface of the copper foil is hot-pressed onto the first thermally conductive adhesive layer. A heating layer consisting of an electrode portion and a heating portion is prepared on the second surface of the copper foil by an etching process; A second thermally conductive adhesive layer is applied to the heating layer, and a second insulating layer is hot-pressed onto the second thermally conductive adhesive layer. A hollowed-out portion is created by laser ablation of the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion is positioned corresponding to the hollowed-out portion.

3. A process for preparing a flexible battery heating film, characterized in that, Includes the following steps: A first thermally conductive adhesive layer with a thickness of 10μm-50μm is coated on the first surface of the copper foil, and a first insulating layer with a thickness of 30μm-60μm is hot-pressed onto the first thermally conductive adhesive layer. A heating layer with a thickness of 30μm-60μm, consisting of an electrode portion and a heating portion, is prepared on the second surface of the copper foil by an etching process. A second thermally conductive adhesive layer with a thickness of 10μm-50μm is coated on the heating layer, and a second insulating layer with a thickness of 30μm-60μm is hot-pressed onto the second thermally conductive adhesive layer. A hollowed-out portion is created by laser ablation of the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion is positioned corresponding to the hollowed-out portion. The heating section includes straight copper foil and wavy copper foil. The wavy copper foil is evenly distributed on the heating film. The straight copper foil and the wavy copper foil form the heating zone, and the area without copper foil is the heating blank zone. The heated blank area is filled with thermally conductive adhesive.

4. A process for preparing a flexible battery heating film, characterized in that, Includes the following steps: A first thermally conductive adhesive layer with a thickness of 10μm-50μm is coated on the surface of a first insulating layer with a thickness of 30μm-60μm, and the first surface of the copper foil is hot-pressed onto the first thermally conductive adhesive layer. A heating layer with a thickness of 30μm-60μm, consisting of an electrode portion and a heating portion, is prepared on the second surface of the copper foil by an etching process. A second thermally conductive adhesive layer with a thickness of 10μm-50μm is coated on the heating layer, and a second insulating layer with a thickness of 30μm-60μm is hot-pressed onto the second thermally conductive adhesive layer. A hollowed-out portion is created by laser ablation of the second insulating layer and the second thermally conductive adhesive layer, and the electrode portion is positioned corresponding to the hollowed-out portion. The heating section includes straight copper foil and wavy copper foil. The wavy copper foil is evenly distributed on the heating film. The straight copper foil and the wavy copper foil form the heating zone, and the area without copper foil is the heating blank zone. The heating blank area is filled with thermally conductive adhesive, and the heat from the heating part diffuses to the heating blank area.

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