A flame-retardant insulating film for new energy batteries and its production method

Abstract

This invention discloses a flame-retardant insulating film for new energy batteries and its production method, belonging to the field of new energy battery technology. The flame-retardant insulating film for new energy batteries includes a heat-conducting layer, a flame-retardant layer, and a protective layer connected sequentially from bottom to top. Both the flame-retardant layer and the protective layer are made of insulating and flame-retardant PC material. The heat-conducting layer includes a heat-absorbing layer and a heat-dissipating layer, with the upper surface of the heat-dissipating layer connected to the flame-retardant layer. The heat-absorbing layer prepared by this invention using PEEK has good heat absorption performance, and when combined with the heat-dissipating layer, it can accelerate heat dissipation, prevent the temperature of the flame-retardant new energy battery from becoming too high, and avoid providing conditions for combustion. Both the flame-retardant layer and the protective layer are made of insulating and flame-retardant PC material, exhibiting good flame-retardant and insulating properties. Furthermore, the arched holes in the lower and upper shock-absorbing layers can improve impact resistance, preventing external impacts on the flame-retardant new energy battery.

Description

Technical Field

[0001] This invention relates to the field of new energy battery technology, specifically to a flame-retardant insulating film for new energy batteries and its production method. Background Technology

[0002] When using new energy batteries, it is necessary to use new energy battery insulating film. The battery insulating film is an insulating material used inside the battery, mainly to isolate the positive and negative electrodes of the battery and prevent short circuits and leakage. However, the current new energy battery insulating film has poor insulation performance and still cannot meet the usage requirements well.

[0003] Chinese patent CN117162614A discloses a new energy battery insulating film and its manufacturing process, including a thermally conductive layer, an insulating layer and a protective layer. This invention solves the problem that the existing new energy battery insulating film has poor insulation performance and cannot meet the usage requirements well. However, the epoxy resin, PE particles and other materials used in this application do not have good flame retardancy and cannot contribute to the flame retardant properties of the new energy battery. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant insulating film for new energy batteries and its production method, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A flame-retardant insulating film for new energy batteries includes a heat-conducting layer, a flame-retardant layer, and a protective layer connected sequentially from bottom to top. The flame-retardant layer and the protective layer are both made of insulating flame-retardant PC material. The heat-conducting layer includes a heat-absorbing layer and a heat-dissipating layer. The upper surface of the heat-dissipating layer is connected to the flame-retardant layer. The heat-absorbing layer has extension strips connected at equal intervals on the side near the heat-dissipating layer. A first through hole is opened on the heat-dissipating layer near the extension strip, and the first through hole also penetrates the extension strip.

[0007] Preferably, the extension strip extends into the heat dissipation layer and is fixedly connected to the heat dissipation layer, and the extension strip is inclined.

[0008] Preferably, a second through hole is provided at equal intervals above the heat dissipation layer.

[0009] Preferably, the heat-absorbing layer is made of PEEK material.

[0010] Preferably, the heat dissipation layer is prepared as follows: vinyl silicone rubber and boron nitride powder are heated and mixed, and injected into the mold cavity at 150°C with an injection pressure of 120 MPa and a mold temperature controlled at 150°C. After injection molding, a first through hole and a second through hole are opened on the heat dissipation layer.

[0011] Preferably, the vinyl content in the vinyl silicone rubber is 0.2% to 0.3%, the mass ratio of vinyl silicone rubber to boron nitride powder is 3:1-2, and the particle size of the boron nitride powder is 15-20 μm.

[0012] Preferably, the preparation method of the insulating flame-retardant PC material is as follows: the PC raw material is dried at 100-120°C for more than 4 hours, the halogen-free flame-retardant additive, antistatic agent, and stabilizer are heated and mixed with the PC raw material, and injected into the mold cavity at 150°C with an injection pressure of 120 MPa. The material is injected into different molds to form a flame-retardant layer or a protective layer.

[0013] Preferably, the halogen-free flame retardant additive is at least one of aluminum hydroxide and magnesium hydroxide, and the mass ratio of the halogen-free flame retardant additive to the PC raw material is 1:1-2.

[0014] Preferably, the protective layer includes a lower damping layer, an upper damping layer, and a wear-resistant layer. The lower damping layer and the upper damping layer are staggered with arched holes, and the ends of the arched holes are provided with arc-shaped support legs. The lower damping layer and the upper damping layer are bonded together with flame-retardant adhesive, and the upper surface of the upper damping layer is connected to the wear-resistant layer.

[0015] Another technical problem to be solved by the present invention is to provide a method for producing an insulating film for flame-retardant new energy batteries, comprising the following steps:

[0016] Step 1: Take PEEK raw material and dry it at 150℃ for more than 3 hours. Heat the barrel to 380℃ and the injection pressure to 120Mpa. Put the material into the mold at 170℃ and extrude it to form a heat-absorbing layer. Extrude a heat-dissipating layer on the surface of the heat-absorbing layer. After drying, open the first and second through holes on the heat-dissipating layer to form a heat-conducting layer.

[0017] Step 2: Extrude the insulating and flame-retardant PC material into a lower damping layer and an upper damping layer. At the same time, bond the lower damping layer and the upper damping layer together as a whole. Bond a wear-resistant layer to the surface of the upper damping layer to form a protective layer.

[0018] Step 3: Extrude the insulating and flame-retardant PC material into a flame-retardant layer, and then bond the upper and lower surfaces of the flame-retardant layer to the heat-conducting layer and the protective layer with flame-retardant adhesive.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The heat-absorbing layer made of PEEK has good heat absorption effect. When combined with the heat dissipation layer, it can accelerate the heat dissipation effect, prevent the temperature of the flame-retardant new energy battery from getting too high, and avoid providing conditions for combustion. Both the flame-retardant layer and the protective layer are made of insulating flame-retardant PC material, which has good flame-retardant and insulating properties. Furthermore, the arched holes opened on the lower and upper shock-absorbing layers can improve the impact resistance, prevent the impact of external impacts on the flame-retardant new energy battery, and further prevent damage to the flame-retardant new energy battery caused by impacts. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the insulating film structure for flame-retardant new energy batteries according to the present invention.

[0022] In the diagram: 1. Heat-conducting layer; 11. Heat-absorbing layer; 111. Extension strip; 12. Heat dissipation layer; 121. First through hole; 122. Second through hole; 2. Flame-retardant layer; 3. Protective layer; 31. Lower shock-absorbing layer; 311. Arched hole; 312. Arc-shaped support leg; 32. Upper shock-absorbing layer; 33. Wear-resistant layer. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1:

[0025] To address the issue that existing materials such as epoxy resin and PE granules do not possess good flame retardancy and therefore cannot contribute to the performance gain of flame-retardant new energy batteries, please refer to [the relevant documentation / reference]. Figure 1 This embodiment provides the following technical solution:

[0026] A flame-retardant insulating film for new energy batteries includes a heat-conducting layer 1, a flame-retardant layer 2, and a protective layer 3 connected sequentially from bottom to top. The flame-retardant layer 2 and the protective layer 3 are both made of insulating flame-retardant PC material. The insulating flame-retardant PC film has excellent flame retardancy, heat resistance, high voltage resistance, low water absorption, bending resistance, tear resistance, and is not easily broken. The heat-conducting layer 1 includes a heat-absorbing layer 11 and a heat-dissipating layer 12. The upper surface of the heat-dissipating layer 12 is connected to the flame-retardant layer 2. The heat-absorbing layer 11 has extension strips 111 connected at equal intervals on the side near the heat-dissipating layer 12. The heat-dissipating layer 12 has a first through hole 121 near the extension strip 111. The first through hole 121 passes through the extension strip 111. The direction of the first through hole 121 is opposite to the direction of the extension strip 111. The heat absorbed by the extension strip 111 can be transferred out through the first through hole 121, and the heat conducted to the heat-dissipating layer 12 can also be dissipated through the first through hole 121.

[0027] The extension strip 111 extends into the heat dissipation layer 12 and is fixedly connected to the heat dissipation layer 12. The extension strip 111 is set at an angle. By setting the extension strip 111, the connection between the heat absorption layer 11 and the heat dissipation layer 12 can be strengthened, and the heat diffusion area of ​​the heat absorption layer 11 can be increased to improve the heat dissipation effect.

[0028] Second through holes 122 are provided at equal intervals above the heat dissipation layer 12. The second through holes 122 improve the heat dissipation effect of the heat dissipation layer 12. The second through holes 122 are vertically arranged with the first through holes 121, which can improve the heat dissipation effect from both the horizontal and vertical directions of the heat dissipation layer 12.

[0029] The heat dissipation layer 12 is prepared as follows: vinyl silicone rubber and boron nitride powder are heated and mixed. The vinyl content in the vinyl silicone rubber is 0.2%, the mass ratio of vinyl silicone rubber to boron nitride powder is 3:2, and the particle size of the boron nitride powder is 20μm. The mixture is injected into the mold cavity at 150℃ with an injection pressure of 120MPa and the mold temperature is controlled at 150℃. The heat dissipation layer 12 is directly molded on the side of the heat absorption layer 11 where the extension strip 111 is provided, and connected to the heat absorption layer 11 to form an integral whole. At this time, the extension strip 111 is embedded in the heat dissipation layer 12. After molding, a first through hole 121 and a second through hole 122 are opened on the heat dissipation layer 12.

[0030] The preparation method of insulating and flame-retardant PC material is as follows: the PC raw material is dried at 120°C for more than 4 hours, aluminum hydroxide, antistatic agent, stabilizer and PC raw material are heated and mixed, the mass ratio of aluminum hydroxide to PC raw material is 1:1.2, and injected into the mold cavity at 150°C with an injection pressure of 120 MPa. The material is injected into different molds to form flame-retardant layer 2 or protective layer 3.

[0031] The protective layer 3 includes a lower damping layer 31, an upper damping layer 32, and a wear-resistant layer 33. The lower damping layer 31 and the upper damping layer 32 are provided with arched holes 311 offset from each other. The ends of the arched holes 311 are provided with arc-shaped support legs 312. The arched holes 311 and arc-shaped support legs 312 of the lower damping layer 31 and the arc-shaped support legs 312 and arched holes 311 of the upper damping layer 32 are respectively provided. The arched holes 311 on the lower damping layer 31 and the upper damping layer 32 can improve the impact resistance. The arc-shaped support legs 312 are used to connect the lower damping layer 31 and the upper damping layer 32. The lower damping layer 31 and the upper damping layer 32 are bonded with flame-retardant adhesive. The upper surface of the upper damping layer 32 is connected to the wear-resistant layer 33.

[0032] To better illustrate the production process of flame-retardant insulating film for new energy batteries, this embodiment presents a method for producing flame-retardant insulating film for new energy batteries, including the following steps:

[0033] Step 1: Take PEEK raw material and dry it at 150°C for more than 3 hours. Heat the barrel to 380°C and the injection pressure to 120 MPa. Put the material into the mold at 170°C and extrude it. During extrusion, the heat-absorbing layer 11 and the extension strip 111 are extruded separately. Before cooling and drying, the extruded extension strip 111 is glued to the heat-absorbing layer 11 at equal intervals to form the heat-absorbing layer 11. A heat-dissipating layer 12 is extruded on the surface of the heat-absorbing layer 11. After drying, the first through hole 121 and the second through hole 122 are opened on the heat-dissipating layer 12 to form the heat-conducting layer 1.

[0034] Step 2: Extrude the insulating and flame-retardant PC material into a lower damping layer 31 and an upper damping layer 32. At the same time, bond the lower damping layer 31 and the upper damping layer 32 together as a whole. Bond the wear-resistant layer 33 to the surface of the upper damping layer 32 to form a protective layer 3.

[0035] Step 3: Extrude the insulating and flame-retardant PC material into flame-retardant layer 2, and bond the upper and lower surfaces of flame-retardant layer 2 to the thermally conductive layer 1 and the protective layer 3 with flame-retardant adhesive.

[0036] Example 2:

[0037] A flame-retardant insulating film for new energy batteries includes a heat-conducting layer 1, a flame-retardant layer 2, and a protective layer 3 connected sequentially from bottom to top. The heat-conducting layer 1 includes a heat-absorbing layer 11 and a heat-dissipating layer 12.

[0038] The heat-absorbing layer 11 is prepared as follows: PEEK raw material is dried at 150°C for more than 3 hours, and the barrel is heated to 380°C with an injection pressure of 120 MPa. The material is then put into a mold at 170°C and extruded.

[0039] The heat dissipation layer 12 is prepared as follows: vinyl silicone rubber and boron nitride powder are heated and mixed. The vinyl content in the vinyl silicone rubber is 0.2%, the mass ratio of vinyl silicone rubber to boron nitride powder is 3:2, and the particle size of the boron nitride powder is 20μm. The mixture is injected into the mold cavity at 150℃ with an injection pressure of 120MPa and the mold temperature is controlled at 150℃. The heat dissipation layer 12 is directly molded on the side of the heat absorption layer 11 where the extension strip 111 is provided, and connected to the heat absorption layer 11 to form an integral whole. At this time, the extension strip 111 is embedded in the heat dissipation layer 12. After molding, a first through hole 121 and a second through hole 122 are opened on the heat dissipation layer 12.

[0040] The preparation method of insulating and flame-retardant PC material is as follows: the PC raw material is dried at 120°C for more than 4 hours, aluminum hydroxide, antistatic agent, stabilizer and PC raw material are heated and mixed, the mass ratio of aluminum hydroxide to PC raw material is 1:1.2, and injected into the mold cavity at 150°C with an injection pressure of 120 MPa. The material is injected into different molds to form flame-retardant layer 2 or protective layer 3.

[0041] The other structures are the same as in Example 1, and the insulating film is prepared using the method of Example 1.

[0042] Comparative Example 1:

[0043] A flame-retardant insulating film for new energy batteries includes a heat-conducting layer 1, a flame-retardant layer 2, and a protective layer 3 connected sequentially from bottom to top. The heat-conducting layer 1 includes a heat-absorbing layer 11 and a heat-dissipating layer 12.

[0044] The heat-absorbing layer 11 is prepared as follows: PEEK raw material is dried at 150°C for more than 3 hours, and the barrel is heated to 380°C with an injection pressure of 120 MPa. The material is then put into a mold at 170°C and extruded.

[0045] The heat dissipation layer 12 is prepared as follows: vinyl silicone rubber and boron nitride powder are heated and mixed. The vinyl content in the vinyl silicone rubber is 0.2%, the mass ratio of vinyl silicone rubber to boron nitride powder is 3:2, and the particle size of the boron nitride powder is 20μm. The mixture is injected into the mold cavity at 150℃ with an injection pressure of 120MPa and the mold temperature is controlled at 150℃. The heat dissipation layer 12 is directly molded on the side of the heat absorption layer 11 where the extension strip 111 is provided, and connected to the heat absorption layer 11 to form an integral whole. At this time, the extension strip 111 is embedded in the heat dissipation layer 12. After molding, a first through hole 121 and a second through hole 122 are opened on the heat dissipation layer 12.

[0046] The flame-retardant layer 2 and the protective layer 3 are made of PE particles and PVDF particles. The heat-conducting layer 1 and the flame-retardant layer 2 are bonded to both sides of the flame-retardant layer 2 to form an insulating film.

[0047] The insulating films prepared in the above embodiments and comparative examples were subjected to combustion and insulation tests, and the following data were obtained:

[0048] Example 1 Example 2 Comparative Example 1 100% insulation performance 98.42％ 98.65％ 98.44％ Flame retardant rating UL94 V-0 UL94 V-0 UL94 V-1

[0049] The insulation performance of Examples 1, 2, and Comparative Example 1 is not significantly different, and all have high insulation effects. However, the amount of aluminum hydroxide added in Example 2 is increased, and the insulation performance of the insulating film prepared in Example 2 is slightly higher than that in Example 1. However, in terms of flame retardancy, Examples 1 and 2 can both reach UL94 V-0, while the flame retardancy of Comparative Example 2 is lower than that of Examples 1 and 2. The insulating flame retardant PC material used in this application has better flame retardancy.

[0050] In summary, the heat-absorbing layer 11 prepared by PEEK has good heat absorption effect, and together with the heat dissipation layer 12, it can accelerate the heat dissipation effect, prevent the temperature of the flame-retardant new energy battery from being too high, and avoid providing conditions for combustion. Both the flame-retardant layer 2 and the protective layer 3 are made of insulating flame-retardant PC material, which has good flame-retardant and insulating properties. Furthermore, the arched holes 311 opened on the lower damping layer 31 and the upper damping layer 32 can improve the impact resistance, prevent the impact of external impacts on the flame-retardant new energy battery, and further prevent the damage to the flame-retardant new energy battery caused by impacts.

[0051] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing a flame-retardant insulating film for new energy batteries, the insulating film comprising a thermally conductive layer (1), a flame-retardant layer (2), and a protective layer (3) connected sequentially from bottom to top, characterized in that: The flame-retardant layer (2) and the protective layer (3) are both made of insulating flame-retardant PC material. The heat-conducting layer (1) includes a heat-absorbing layer (11) and a heat-dissipating layer (12). The heat-absorbing layer (11) is made of PEEK material. The upper surface of the heat-dissipating layer (12) is connected to the flame-retardant layer (2). The heat-absorbing layer (11) has extension strips (111) connected at equal intervals on one side near the heat-dissipating layer (12). The heat-dissipating layer (12) has a first through hole (121) at the position near the extension strip (111). The first through hole (121) extends through the extension strip. The strip (111) has second through holes (122) at equal intervals above the heat dissipation layer (12); the protective layer (3) includes a lower damping layer (31), an upper damping layer (32) and a wear-resistant layer (33). The lower damping layer (31) and the upper damping layer (32) have arched holes (311) staggered on them. The ends of the arched holes (311) are provided with arc-shaped support legs (312). The lower damping layer (31) and the upper damping layer (32) are bonded together with flame-retardant adhesive. The upper surface of the upper damping layer (32) is connected to the wear-resistant layer (33). The method for producing insulating film includes the following steps: Step 1: Take PEEK raw material and dry it at 150°C for more than 3 hours. Heat the barrel to 380°C and the injection pressure to 120 MPa. Put the material into a mold at 170°C and extrude it to form a heat-absorbing layer (11). Extrude a heat-dissipating layer (12) on the surface of the heat-absorbing layer (11). After drying, open the first through hole (121) and the second through hole (122) on the heat-dissipating layer (12) to form a heat-conducting layer (1). Step 2: Extrude the insulating and flame-retardant PC material into a lower damping layer (31) and an upper damping layer (32), and bond the lower damping layer (31) and the upper damping layer (32) together as a whole. A wear-resistant layer (33) is bonded to the surface of the upper damping layer (32) to form a protective layer (3). Step 3: Extrude the insulating flame-retardant PC material into a flame-retardant layer (2), and bond the upper and lower surfaces of the flame-retardant layer (2) to the heat-conducting layer (1) and the protective layer (3) with flame-retardant adhesive.

2. The method for producing the flame-retardant insulating film for new energy batteries according to claim 1, characterized in that: The extension strip (111) extends into the heat dissipation layer (12) and is fixedly connected to the heat dissipation layer (12). The extension strip (111) is set at an angle.

3. The method for producing the insulating film for flame-retardant new energy batteries according to claim 2, characterized in that: The heat dissipation layer (12) is prepared as follows: take vinyl silicone rubber and boron nitride powder, heat and mix them, and inject them into the mold cavity at 150°C. The injection pressure is 120 MPa, the mold temperature is controlled at 150°C, and injection molding is performed. After molding, a first through hole (121) and a second through hole (122) are opened on the heat dissipation layer (12).

4. The method for producing the insulating film for flame-retardant new energy batteries according to claim 3, characterized in that: The vinyl silicone rubber contains 0.2% to 0.3% vinyl content, the mass ratio of vinyl silicone rubber to boron nitride powder is 3:1-2, and the particle size of the boron nitride powder is 15-20 μm.

5. The method for producing the insulating film for flame-retardant new energy batteries according to claim 4, characterized in that: The preparation method of the insulating flame-retardant PC material is as follows: the PC raw material is dried at 100-120℃ for more than 4 hours, the halogen-free flame-retardant additive, antistatic agent, stabilizer and PC raw material are heated and mixed, and injected into the mold cavity at 150℃ with an injection pressure of 120Mpa. The material is injected into different molds to form a flame-retardant layer (2) or a protective layer (3).

6. The method for producing the flame-retardant insulating film for new energy batteries according to claim 5, characterized in that: The halogen-free flame retardant additive is at least one of aluminum hydroxide and magnesium hydroxide, and the mass ratio of the halogen-free flame retardant additive to the PC raw material is 1:1-2.

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