All-solid-state film lithium ion battery protection film

Abstract

The utility model discloses a protective film for an all-solid-state film lithium ion battery. The protective film comprises an upper protective layer, an upper foaming silica gel layer, an upper temperature-resistant layer, an upper resin layer, a carrier layer, a lower resin layer, a lower temperature-resistant layer, a lower foaming silica gel layer and a lower protective layer which are sequentially attached from top to bottom. The heat of the lithium ion battery can be absorbed through the upper and lower foaming silica gel layers, so that heat accumulation is prevented, and meanwhile, the effects of impact buffering and fire and combustion prevention are achieved; the high temperature resistance can be improved through the upper temperature-resistant layer and the lower temperature-resistant layer, the heat stability is good, deformation or combustion is not prone to occurring, the safety is improved, the surface bonding performance can be greatly improved through the upper resin layer and the lower resin layer, the surface tension of the film is enhanced, and the attaching effect is improved; the upper protection layer and the lower protection layer can prevent abrasion or scratching, and the protection effect is good; the carrier layer is a PDMS film, a PCL film or a BOPP film, has excellent mechanical properties and good ductility, is beneficial to product processing and molding, and has good comprehensive performance.

Description

Technical Field

[0001] The utility model relates to the technical field of thin films, in particular to an all-solid-state thin film lithium ion battery protective film. Background Art

[0002] Thin-film all-solid-state lithium battery is a new type of lithium-ion battery developed on the basis of traditional lithium-ion battery. It has extremely high safety. Its solid electrolyte is non-flammable, non-corrosive, non-volatile, and non-leaking. It also overcomes the lithium dendrite phenomenon. The basic working principle of the protective film of all-solid-state thin-film lithium-ion battery is similar to that of traditional lithium-ion battery, that is, during the charging process, Li + It comes out from the positive electrode film and undergoes a reduction reaction in the negative electrode film through the electrolyte; the discharge process is the opposite.

[0003] The all-solid-state thin-film lithium-ion battery protective film uses solid electrolytes. In order to protect the solid electrolyte layer and prevent it from contacting the positive and negative electrode layers, a protective film is required to separate them. Since the positive and negative electrode layers of the all-solid-state thin-film lithium-ion battery protective film are planar film forms, although the surface area is increased, the ductility and processability of the battery are improved, the all-solid-state thin-film lithium-ion protective film has the risk of impact breakdown. When the battery temperature is too high, the protective film material will start the "closed-cell function" to curb the current conduction inside the battery. However, if the micropore tortuosity of the protective film is too small, its puncture strength will be significantly reduced, thereby increasing the risk of short circuit caused by contact between the positive and negative electrodes. In addition, in a high temperature environment, the protective film material is prone to deformation or combustion, further exacerbating the safety hazards of lithium batteries. Therefore, when manufacturing all-solid-state thin-film lithium-ion battery protective films, these factors need to be fully considered to ensure the safety and stability of the battery. However, the existing commercial protective films are mostly made of PVC or PE materials, which are very easy to deform at high temperatures and have poor heat dissipation. If too much heat accumulates, the protective film will melt through, and the positive and negative electrodes will contact and catch fire or even explode. Therefore, it is necessary to develop a high-performance protective film for lithium-ion batteries that is resistant to high temperatures, conducive to heat conduction, prevents heat accumulation, and has good protective effects. Utility Model Content

[0004] In view of the above-mentioned deficiencies, the utility model aims to provide a high-performance protective film for lithium-ion batteries which has a reasonable structural design, is resistant to high temperatures, is conducive to conducting heat, prevents heat accumulation, and has good protective effect.

[0005] In order to achieve the above-mentioned purpose, the utility model provides the following technical solutions:

[0006] A fully solid-state thin-film lithium-ion battery protective film comprises a carrier layer, an upper protective layer, a lower protective layer, an upper foamed silicone layer, a lower foamed silicone layer, an upper temperature-resistant layer, a lower temperature-resistant layer, an upper resin layer and a lower resin layer, wherein the upper protective layer, the upper foamed silicone layer, the upper temperature-resistant layer, the upper resin layer, the carrier layer, the lower resin layer, the lower temperature-resistant layer, the lower foamed silicone layer and the lower protective layer are sequentially laminated in order from top to bottom.

[0007] As a preferred solution of the utility model, the thickness of the upper protective layer or the lower protective layer is 50 to 90 microns. The upper protective layer or the lower protective layer is an explosion-proof film or a silicone protective film, which has good exhaust effect, low adhesion, stable peeling force after attachment, and good protection effect to prevent wear or scratches.

[0008] As a preferred embodiment of the utility model, the thickness of the upper foamed silicone layer or the lower foamed silicone layer is 25 to 60 microns. The upper foamed silicone layer and the lower foamed silicone layer are made of foamed silicone sheets, also called addition-type silicone, with tear strength: 55Kn / m; ductility: 100%; temperature resistance range: -40-220℃; fire rating: 94V-0. The foamed silicone sheet has excellent electrical properties and chemical stability, can absorb the heat of lithium-ion batteries, prevent heat accumulation, and play the role of impact buffering and fire prevention and combustion prevention.

[0009] As a preferred solution of the utility model, the upper temperature-resistant layer or the lower temperature-resistant layer has a thickness of 50 to 120 microns. The upper temperature-resistant layer or the lower temperature-resistant layer is a polytetrafluoroethylene film or a PI film, which has good high temperature resistance. The polytetrafluoroethylene film can be used continuously at 250-300°C and can withstand higher temperatures in a short period of time. The PI film can be used at a temperature of about 300°C for a long time and 400 to 450°C for a short period of time.

[0010] As a preferred embodiment of the present invention, the thickness of the upper resin layer or the lower resin layer is 5 to 8 microns. The upper resin layer or the lower resin layer can be epoxy resin 828, phenolic epoxy resin (F-44 type) or polysulfone resin, which can greatly improve the surface adhesion performance, enhance the surface tension of the film, and facilitate the close fitting between the upper and lower temperature-resistant layers and the carrier layer to prevent bubbles or falling off.

[0011] As a preferred solution of the utility model, the thickness of the carrier layer is 20 to 35 microns, and the carrier layer is a PDMS film, a PCL film or a BOPP film, which has excellent mechanical properties and good ductility.

[0012] The beneficial effects of the utility model are as follows: the utility model has a reasonable structural design, and the upper and lower foamed silicone layers can absorb the heat of the lithium-ion battery to prevent heat accumulation, and at the same time play the role of impact buffering and fire prevention and combustion prevention; the upper and lower temperature-resistant layers can improve the high temperature resistance, good thermal stability, not easy to deform or burn, and improve safety; the upper and lower resin layers can greatly improve the surface adhesion performance, enhance the tension of the film surface, and improve the fitting effect; the upper and lower protective layers can prevent wear or scratches, and have a good protective effect; the carrier layer is a PDMS film, a PCL film or a BOPP film, which has excellent mechanical properties and good ductility, is convenient for the curling of solid-state thin-film batteries, and is beneficial to product processing and molding, with good comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the cross-sectional structure of the utility model. DETAILED DESCRIPTION

[0014] Example 1: See Figure 1 An embodiment of the utility model provides an all-solid-state thin-film lithium-ion battery protective film, which comprises an upper protective layer 1, an upper foamed silicone layer 2, an upper temperature-resistant layer 3, an upper resin layer 4, a carrier layer 5, a lower resin layer 6, a lower temperature-resistant layer 7, a lower foamed silicone layer 8 and a lower protective layer 9 which are laminated in order from top to bottom.

[0015] Among them, the thickness of the carrier layer 5 is preferably a 25-micron PDMS film. The material of the upper resin layer 4 and the lower resin layer 6 is preferably epoxy resin 828, which is coated on the upper and lower surfaces of the carrier layer 5 using a micro-concave coater. The thickness is controlled to be 5 microns, and its viscosity is kept at 1200gf / inch, which can greatly improve the surface bonding performance and enhance the surface tension of the film, which is conducive to the close fit between the upper temperature-resistant layer 3 and the lower temperature-resistant layer 7 and the carrier layer 5, preventing bubbles and layer-to-layer shedding. The upper protective layer 1 and the lower protective layer 9 are preferably silicone protective films with a thickness of 70 microns. The thickness of the upper foamed silicone layer 2 and the lower foamed silicone layer 8 is preferably 38 microns, which has excellent electrical properties and chemical stability, can absorb the heat of lithium-ion batteries, prevent heat accumulation, and play a role in impact buffering and fire prevention and combustion prevention. The upper temperature-resistant layer 3 and the lower temperature-resistant layer 7 are preferably polytetrafluoroethylene films with a thickness of 60 microns, which have good high temperature resistance.

[0016] Embodiment 2: The embodiment of the utility model provides an all-solid-state thin-film lithium-ion battery protective film, which is basically the same as the structure of embodiment 1, except that the thickness of the carrier layer 5 is preferably a 30-micron BOPP film. The material of the upper resin layer 4 and the lower resin layer 6 is preferably polysulfone resin, which is coated on the upper and lower surfaces of the carrier layer 5 using a micro-concave coater, and the thickness is controlled to be 7 microns, and its viscosity is maintained at 1000gf / inch. The upper protective layer 1 and the lower protective layer 9 are preferably explosion-proof films with a thickness of 50 microns, such as AGAF explosion-proof film (SDK1025AG-3) or high wear-resistant explosion-proof film (SDK1025N-4). The thickness of the upper foamed silicone layer 2 and the lower foamed silicone layer 8 is preferably 45 microns. The upper temperature-resistant layer 3 and the lower temperature-resistant layer 7 are preferably PI films with a thickness of 100 microns.

[0017] Embodiment 3: The embodiment of the utility model provides an all-solid-state thin-film lithium-ion battery protective film, which is basically the same as the structure of embodiment 1, except that the thickness of the carrier layer 5 is preferably a PCL film of 20 microns. The upper resin layer 4 is preferably made of phenolic epoxy resin (F-44 type), which is coated on the upper surface of the carrier layer 5 by a micro-concave coater, and its thickness is controlled to be 5 microns. The material of the lower resin layer 6 is preferably polysulfone resin, which is coated on the lower surface of the carrier layer 5 by a micro-concave coater, and its thickness is controlled to be 5 microns. The upper protective layer 1 is preferably an explosion-proof film with a thickness of 55 microns. The lower protective layer 9 is preferably a silicone protective film with a thickness of 60 microns. The thickness of the upper foamed silicone layer 2 is preferably 25 microns. The thickness of the lower foamed silicone layer 8 is preferably 30 microns. The upper temperature-resistant layer 3 is preferably a polytetrafluoroethylene film with a thickness of 50 microns. The lower temperature-resistant layer 7 is preferably a PI film with a thickness of 50 microns.

[0018] Embodiment 4: The embodiment of the utility model provides an all-solid-state thin-film lithium-ion battery protective film, which is basically the same as the structure of embodiment 1, except that the thickness of the carrier layer 5 is preferably a PDMS film of 35 microns. The upper resin layer 4 is preferably made of epoxy resin 828, and is coated on the upper surface of the carrier layer 5 by a micro-concave coater, and its thickness is controlled to be 8 microns. The material of the lower resin layer 6 is preferably polysulfone resin, and is coated on the lower surface of the carrier layer 5 by a micro-concave coater, and its thickness is controlled to be 8 microns. The upper protective layer 1 is preferably a silicone protective film with a thickness of 90 microns. The lower protective layer 9 is preferably an explosion-proof film with a thickness of 80 microns. The thickness of the upper foamed silicone layer 2 is preferably 60 microns. The thickness of the lower foamed silicone layer 8 is preferably 50 microns. The upper temperature-resistant layer 3 is preferably a PI film with a thickness of 120 microns. The lower temperature-resistant layer 7 is preferably a polytetrafluoroethylene film with a thickness of 110 microns.

[0019] The above embodiments are only preferred implementation modes of the present utility model. The present utility model cannot list all implementation modes one by one. Any technical solution adopting one of the above embodiments, or equivalent changes made according to the above embodiments, are within the protection scope of the present utility model.

[0020] During production, the carrier layer 5 is a PDMS film, a PCL film or a BOPP film, which has excellent mechanical properties and good ductility, is convenient for the curling of the solid-state thin-film battery, and is also beneficial for product processing and molding, with good comprehensive performance; when in use, the upper foamed silicone layer 2 and the lower foamed silicone layer 8 are used to absorb the heat of the lithium-ion battery to prevent heat accumulation, and at the same time play the role of impact buffering and fire prevention and combustion prevention; the upper temperature-resistant layer 3 and the lower temperature-resistant layer 7 can improve the high temperature resistance, have good thermal stability, are not easy to deform or burn, and improve safety.

[0021] According to the disclosure and teaching of the above specification, technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the specific implementations disclosed and described above, and some modifications and changes to the utility model should also fall within the scope of protection of the claims of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the utility model. Other membranes that are the same or similar to them are all within the scope of protection of the utility model.

Claims

1. An all-solid-state thin-film lithium-ion battery protective film, comprising a carrier layer, characterized in that: It also includes an upper protective layer, a lower protective layer, an upper foamed silicone layer, a lower foamed silicone layer, an upper temperature-resistant layer, a lower temperature-resistant layer, an upper resin layer and a lower resin layer. The upper protective layer, the upper foamed silicone layer, the upper temperature-resistant layer, the upper resin layer, the carrier layer, the lower resin layer, the lower temperature-resistant layer, the lower foamed silicone layer and the lower protective layer are sequentially bonded in order from top to bottom.

2. The all-solid-state thin-film lithium-ion battery protective film according to claim 1, characterized in that: The thickness of the upper protective layer or the lower protective layer is 50 to 90 microns.

3. The all-solid-state thin-film lithium-ion battery protective film according to claim 1 or 2, characterized in that: The upper protective layer or the lower protective layer is an explosion-proof film or a silicone protective film.

4. The all-solid-state thin-film lithium-ion battery protective film according to claim 1, characterized in that: The thickness of the upper foamed silica gel layer or the lower foamed silica gel layer is 25 to 60 microns.

5. The all-solid-state thin-film lithium-ion battery protective film according to claim 1, characterized in that: The upper temperature-resistant layer or the lower temperature-resistant layer has a thickness of 50 to 120 microns.

6. The all-solid-state thin-film lithium-ion battery protective film according to claim 1 or 5, characterized in that: The upper temperature-resistant layer or the lower temperature-resistant layer is a polytetrafluoroethylene film or a PI film.

7. The all-solid-state thin-film lithium-ion battery protective film according to claim 1, characterized in that: The thickness of the upper resin layer or the lower resin layer is 5 to 8 microns.

8. The all-solid-state thin-film lithium-ion battery protective film according to claim 1, characterized in that: The thickness of the carrier layer is 20 to 35 microns.

9. The all-solid-state thin-film lithium-ion battery protective film according to claim 1 or 8, characterized in that: The carrier layer is a PDMS film, a PCL film or a BOPP film.

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