Membrane containing organic-inorganic hybrid layer, and preparation method, production system and application thereof

Abstract

The invention provides a membrane containing an organic-inorganic hybrid layer as well as a preparation method, a production system and application of the membrane. The membrane containing the organic-inorganic hybrid layer comprises a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer. The preparation method of the film containing the organic-inorganic hybrid layer comprises the following steps: feeding reaction gas and a precursor carried by carrier gas into a non-discharge area; and discharging the discharge gas through high-voltage alternating current to generate a plasma region, feeding the reaction gas and a precursor carried by the carrier gas into the plasma region to react, so that the porous substrate is adsorbed through at least one non-discharge region, and then is deposited through at least one plasma region. When the membrane containing the organic-inorganic hybrid layer is used as a battery diaphragm, excellent battery performance can be obtained, and the original basic characteristics of the diaphragm are hardly influenced.

Description

Technical Field

[0001] The invention belongs to the field of membrane materials, and relates to a membrane containing an organic-inorganic hybrid layer, a preparation method, a production system and an application thereof. Background Art

[0002] Nanoparticle membrane material is a thin film material containing nanoparticles with porous structure, large specific surface area effect and small size effect. It has a wide range of applications in many fields, such as filtration and separation, sensors, catalysis, energy storage and conversion, drug delivery, optical devices, biomedicine, automobiles, electronics, elastomers, packaging, plastics, medical, optics, solar cells and battery manufacturing.

[0003] Due to the high surface energy of nanoparticles, they tend to aggregate during production, storage, and solution application, forming large-scale agglomerates that do not achieve the effect of monodisperse nanoparticles. In the process of preparing nanoparticle films, it is difficult to control the thickness of the nanoparticle film, especially for thinner films, where uniformity and continuity are difficult to control. Since organic substrates and inorganic nanoparticles are non-adhesive, in order to prepare uniform films, it is necessary to control the stability of the particles. Surface modification and the addition of dispersants, binders, coupling agents, etc. are generally used to improve stability.

[0004] CN108767177B discloses a ceramic coating composite diaphragm containing an aqueous adhesive. This diaphragm coating technology is currently widely used in the industry. It is prepared by coating an organic / inorganic composite coating mixed with inorganic particles and a binder on the surface of a polymer substrate. It has the advantages of high coating efficiency, good consistency, and low cost. However, in the process of actual application, this type of composite diaphragm still has a series of problems, such as the production process of inorganic powders and the high energy consumption of the binder drying process, the agglomeration of ceramic particles in the slurry, the coating thickness requires at least 1 to several microns (thinner coatings will cause coating uniformity problems), the interface wettability between the coating and the substrate is poor, the use of the binder blocks the microporous structure on the surface of the base film, reduces the ionic conductivity, and the bonding force between the coating and the substrate is significantly affected by the distribution of the binder. The coating layer of this type of composite diaphragm has poor bonding with the base film layer, resulting in cracking, aging, porosity changes, and ceramic particles falling off in the coating process, long-term circulation, or battery abuse. The ionic conductivity of the diaphragm is deteriorated, and even safety problems are caused in severe cases.

[0005] CN109962198B discloses a composite diaphragm with an inorganic dielectric layer that does not contain a binder. By adjusting the thickness of the inorganic dielectric layer, the thermal shrinkage of the diaphragm can be improved and the battery safety can be improved. The composite diaphragm adopts a low-pressure vapor deposition method to prepare the inorganic dielectric layer, retaining the ion conduction channel. However, since this method uses a gaseous deposition method under a vacuum environment, the deposited layer is a dense film, and as the thickness increases, the porosity of the diaphragm will decrease or even block the holes, the energy consumption is high, the processing time is long, and a vacuum is required, which lacks industrial practicality.

[0006] CN104810495B discloses a composite diaphragm, comprising a porous substrate and a porous organic-inorganic hybrid dielectric layer disposed on at least one side of the substrate. The organic-inorganic hybrid dielectric layer is prepared by a normal pressure gas phase chemical reaction polymerization deposition method, which avoids the problem of clogging, realizes a porous structure and a high specific surface area, and retains an ion conduction channel. The porous organic-inorganic hybrid dielectric layer contains organic-inorganic hybrid nanoparticles, which increase the specific surface area of ​​the diaphragm while enhancing the adhesion between the dielectric layer and the polymer diaphragm, and effectively improves the heat shrinkage resistance and hydrophilicity of the diaphragm. Compared with the ceramic coating composite diaphragm (wet coating) containing an aqueous adhesive, this technology is a dry normal pressure deposition, which effectively reduces energy consumption and cost. The nanoparticles containing organic and inorganic components firmly connected to the base membrane increase the membrane breaking temperature of the base membrane, improve the safety performance of the battery, and can be applied to the online coating preparation of secondary battery diaphragms and other occasions. However, since the products of this process only use a single reactor, the processing time is relatively long, and the plasma will destroy the base film structure during the processing, resulting in a decrease in mechanical properties. At the same time, only a small amount of particles enter the base film, which cannot provide sufficient support for the structure of the diaphragm. The deposition efficiency, nanoparticle coverage, film rupture temperature and mechanical properties of this process need to be further improved. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a membrane containing an organic-inorganic hybrid layer, a preparation method, a production system and an application thereof. The membrane containing an organic-inorganic hybrid layer of the present invention can be used as a secondary battery separator and has improved secondary battery properties.

[0008] Specifically, one aspect of the present invention provides a membrane containing an organic-inorganic hybrid layer, wherein the membrane containing an organic-inorganic hybrid layer comprises a porous matrix layer and an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer located on one side or both sides of the porous matrix layer, wherein the organic-inorganic hybrid transition layer is located between the porous matrix layer and the organic-inorganic hybrid surface layer;

[0009] The porous matrix layer contains fibers and does not contain organic-inorganic hybrid nanoparticles;

[0010] The organic-inorganic hybrid transition layer comprises fibers and organic-inorganic hybrid nanoparticles;

[0011] The organic-inorganic hybrid surface layer comprises organic-inorganic hybrid nanoparticles but does not comprise fibers;

[0012] The total thickness of the film containing the organic-inorganic hybrid layer is 1 to 30 μm;

[0013] The thickness of the organic-inorganic hybrid transition layer is 1% to 80% of the total thickness of the film containing the organic-inorganic hybrid layer, and the average particle size of the organic-inorganic hybrid nanoparticles in the organic-inorganic hybrid transition layer is 1 to 50 nm;

[0014] The thickness of the organic-inorganic hybrid surface layer is 0.8% to 6% of the total thickness of the film containing the organic-inorganic hybrid layer, and the average particle size of the organic-inorganic hybrid nanoparticles in the organic-inorganic hybrid surface layer is 1 to 200 nm.

[0015] In one or more embodiments, the fiber is made of one or more selected from synthetic fibers and natural fibers.

[0016] In one or more embodiments, the synthetic fiber is selected from one or more of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide, and polyamide.

[0017] In one or more embodiments, the membrane containing the organic-inorganic hybrid layer is prepared by plasma chemical vapor deposition reaction of precursors and reaction gases inside and on the surface of a porous matrix.

[0018] In one or more embodiments, the precursor comprises a first precursor, which is one or more compounds containing one or more elements selected from silicon, aluminum, titanium, zirconium, calcium, magnesium, zinc and barium and one or more elements selected from oxygen, carbon, nitrogen, hydrogen, sulfur, fluorine and chlorine, or their active gases, wherein the active gas is a substance formed by the conversion of the compounds through the action of high-energy particles.

[0019] In one or more embodiments, the first precursor is one or more organosilicon compounds or reactive gases thereof.

[0020] In one or more embodiments, the organosilicon compound is selected from one or more of silane, polydimethylsiloxane, hexamethyldisiloxane, octamethylcyclotetrasiloxane, tetraethylcyclotetrasiloxane, dimethylsiloxane, tetraethylorthosilicate, vinyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, vinyltriethoxysilane and vinyltrimethoxysilane.

[0021] In one or more embodiments, the precursor further comprises a second precursor, which is one or more compounds selected from water, ethanol, acetic acid, acrylic acid, acrylate, tannic acid, sulfonic acid and sulfonic acid ester, or their active gases, wherein the active gas is a substance formed by the conversion of the compounds through the action of high-energy particles.

[0022] In one or more embodiments, the precursor further comprises a reactive gas of the first or second precursor, wherein the reactive gas is a substance formed by converting a compound through the action of high-energy particles (such as electron beams, ion beams, pulsed lasers, radio frequencies, etc.). The first or second precursor is converted into the reactive precursor gas, and the reactive precursor gas is then introduced into the plasma region for reaction.

[0023] In one or more embodiments, the reaction gas comprises one or more of oxygen, nitrogen, carbon dioxide, and air.

[0024] Another aspect of the present invention provides a method for preparing a membrane containing an organic-inorganic hybrid layer as described in any embodiment of the present invention, wherein the method is a regional combined atmospheric pressure plasma chemical vapor deposition method, and the regional combined atmospheric pressure plasma chemical vapor deposition method comprises: introducing a reaction gas and a precursor carried by a carrier gas into at least one plasma reactor without applying a voltage to generate at least one non-discharge region; introducing a discharge gas into at least one plasma reactor, causing the discharge gas to discharge by high-voltage alternating current to generate at least one plasma region, and introducing the reaction gas and the precursor carried by the carrier gas into the plasma region for reaction; allowing a porous substrate to first pass through at least one non-discharge region for adsorption, and then pass through at least one plasma region for a deposition reaction, wherein the reaction product is deposited on the porous substrate to obtain the membrane containing the organic-inorganic hybrid layer.

[0025] In one or more embodiments, in each plasma region, the discharge gas is one or both selected from argon and helium.

[0026] In one or more embodiments, in each plasma region, the carrier gas is one or more selected from argon, helium, nitrogen, and air.

[0027] In one or more embodiments, the porous matrix passes through each plasma zone for a time period of 1 to 60 seconds.

[0028] In one or more embodiments, the number of the plasma regions is 1 to 5, such as 1 to 3, or 1 to 2.

[0029] In one or more embodiments, in each plasma region, the volume flow ratio of the carrier gas carrying the precursor to the reaction gas is 1:30 to 600:1.

[0030] In one or more embodiments, the volume concentration of the precursor in the carrier gas carrying the precursor in each plasma region is 500-5000 ppm.

[0031] In one or more embodiments, in each plasma region, the total flow rate of the carrier gas carrying the precursor and the reaction gas is 1 to 30 SLM respectively.

[0032] In one or more embodiments, in each plasma region, a volume flow ratio of the reaction gas to the discharge gas may be 1:2 to 1:1000.

[0033] In one or more embodiments, the peak voltage of the high voltage alternating current in each plasma region is 500 to 30,000 V.

[0034] In one or more embodiments, in each plasma region, the high voltage alternating current is a sinusoidal, cosine or pulsed alternating current, the frequency of the sinusoidal and cosine alternating currents is 10 to 300 kHz, the pulse frequency of the pulsed alternating current is 30 to 100 kHz, the pulse width is 5 to 1000 ns, the pulse rising edge is less than 50 ns, and the pulse duty cycle is 1% to 99%.

[0035] In one or more embodiments, a dielectric barrier discharge is used to generate the plasma.

[0036] In one or more embodiments, in each non-discharge region, the carrier gas is one or more selected from argon, helium, nitrogen and air.

[0037] In one or more embodiments, the time for the porous matrix to pass through each non-discharge zone is 1 to 60 seconds.

[0038] In one or more embodiments, the number of the non-discharge regions is 1 to 5, such as 1 to 3, or 1 to 2.

[0039] In one or more embodiments, in each non-discharge region, the volume flow ratio of the carrier gas carrying the precursor to the reaction gas is 1:30 to 600:1.

[0040] In one or more embodiments, in each non-discharge region, the volume concentration of the precursor in the carrier gas carrying the precursor is 500-5000 ppm.

[0041] In one or more embodiments, in each non-discharge region, the total flow rate of the carrier gas carrying the precursor and the reaction gas is 1 to 30 SLM.

[0042] In one or more embodiments, the number of plasma regions is at least two, and at least one non-discharge region is respectively arranged before the first plasma region and between each two adjacent plasma regions, so that the porous matrix passes through one or more non-discharge regions before passing through each plasma region.

[0043] In one or more embodiments, the number of non-discharge regions is two, the number of plasma regions is two, the porous substrate is passed through the first non-discharge region, the first precursor and the reaction gas are loaded but not discharged for adsorption; the porous substrate is then passed through the first plasma region, the first precursor and the reaction gas are loaded for discharge deposition; the porous substrate is then passed through the second non-discharge region, the first precursor and / or the second precursor and the reaction gas are loaded but not discharged for adsorption; the porous substrate is then passed through the second plasma region, the first precursor and / or the second precursor and the reaction gas are loaded for discharge deposition.

[0044] Another aspect of the present invention provides a production system for preparing a film containing an organic-inorganic hybrid layer as described in any embodiment of the present invention or for implementing a method as described in any embodiment of the present invention, wherein the production system comprises two or more plasma reactors.

[0045] In one or more embodiments, the plasma reactor is a dielectric barrier plasma reactor.

[0046] In one or more embodiments, the electrode of the dielectric barrier plasma reactor is selected from one or more of a comb electrode, a showerhead electrode, a coplanar electrode, a flat electrode, and a rod electrode.

[0047] Another aspect of the present invention provides the use of a membrane containing an organic-inorganic hybrid layer as described in any embodiment of the present invention, or a membrane containing an organic-inorganic hybrid layer prepared by the method described in any embodiment of the present invention in water treatment materials or devices, drug delivery materials or devices, drug separation materials or devices, biological fluid separation materials or devices, blood separation materials or devices, sensors, energy storage materials or devices, energy conversion materials or devices, drug delivery materials or devices, optical materials or devices, or optoelectronic materials or devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of the structure of a membrane containing an organic-inorganic hybrid layer in some embodiments of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0050] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0051] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0052] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0053] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0054] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0055] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0056] The membrane containing an organic-inorganic hybrid layer of the present invention (hereinafter referred to as the membrane of the present invention) includes a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer. Among them, the organic-inorganic hybrid transition layer is located between the porous matrix layer and the organic-inorganic hybrid surface layer. In some embodiments, the membrane containing an organic-inorganic hybrid layer of the present invention is composed of a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer. In the present invention, the organic-inorganic hybrid transition layer and the organic-inorganic hybrid surface layer can be collectively referred to as an organic-inorganic hybrid layer. The organic-inorganic hybrid transition layer and the organic-inorganic hybrid surface layer can exist on one side or both sides of the porous matrix layer of the membrane of the present invention, that is, the membrane of the present invention can sequentially include a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer in the thickness direction, or sequentially include a first organic-inorganic hybrid surface layer, a first organic-inorganic hybrid transition layer, a porous matrix layer, a second organic-inorganic hybrid transition layer and a second organic-inorganic hybrid surface layer. In some embodiments, such as Figure 1 As shown, there are organic-inorganic hybrid transition layers and organic-inorganic hybrid surface layers on both sides of the porous matrix layer of the membrane of the present invention.

[0057] The total thickness of the film containing the organic-inorganic hybrid layer of the present invention can be 1 to 30 μm, for example, 2 μm, 5 μm, 8 μm, 9 μm, 10 μm, 12 μm, 15 μm, 16 μm, 20 μm, or 25 μm.

[0058] In the present invention, the porous matrix layer contains fibers. The porous matrix layer does not contain organic-inorganic hybrid nanoparticles. In some embodiments, the porous matrix layer is composed of fibers. The part of the porous matrix used in the preparation of the membrane containing the organic-inorganic hybrid layer of the present invention that is not modified by the organic-inorganic hybrid nanoparticles forms a porous matrix layer. The material of the fiber in the porous matrix is ​​a polymer, which can be one or more synthetic fibers and natural fibers selected from polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, etc. Polyamide includes aromatic polyamide, semi-aromatic polyamide and aliphatic polyamide. The porous matrix can be a porous ultrafine fiber membrane or plate formed by wet spinning, melt spinning, electrostatic spinning, flash spinning and other preparation methods. The average pore size of the porous matrix layer can be 20 to 500nm, for example 50nm, 100nm, 200nm, 300nm, 400nm. The porosity of the porous matrix layer may be 20% to 80%, for example, 30%, 40%, 50%, 60%, or 70%.

[0059] Compared with the porous substrate as a raw material, the thickness of the membrane containing the organic-inorganic hybrid layer of the present invention changes by 0.8% to 6%, the upper limit of the average pore size change rate is 5% or less, and the upper limit of the porosity change rate is -10% or less.

[0060] In the present invention, the organic-inorganic hybrid transition layer (abbreviated as transition layer) comprises fibers and organic-inorganic hybrid nanoparticles located on the fiber surface and in the fiber gaps, and is a transition layer located between the porous matrix layer and the organic-inorganic hybrid surface layer. In some embodiments, the organic-inorganic hybrid transition layer consists of fibers and organic-inorganic hybrid nanoparticles located on the fiber surface and in the fiber gaps.

[0061] In the present invention, the thickness of the organic-inorganic hybrid transition layer can be 1% to 80% of the total thickness of the film containing the organic-inorganic hybrid layer, such as 2%, 5%, 10%, 25%, 50%, 65%, 70%. When there are organic-inorganic hybrid transition layers on both sides of the porous matrix layer, the thickness of the aforementioned organic-inorganic hybrid transition layer refers to the total thickness of the two organic-inorganic hybrid transition layers. The average particle size of the organic-inorganic hybrid nanoparticles in the organic-inorganic hybrid transition layer can be 1 to 50 nm, such as 2 nm, 5 nm, 10 nm, 12 nm, 15 nm, 17 nm, 20 nm, 30 nm, 40 nm.

[0062] In the present invention, the organic-inorganic hybrid surface layer (surface layer for short) comprises organic-inorganic hybrid nanoparticles located on the surface of the film containing the organic-inorganic hybrid layer, and is the surface layer of the film containing the organic-inorganic hybrid layer. In some embodiments, the organic-inorganic hybrid surface layer is composed of organic-inorganic hybrid nanoparticles located on the surface of the film containing the organic-inorganic hybrid layer.

[0063] In the present invention, the thickness of the organic-inorganic hybrid surface layer can be 0.8% to 6% of the total thickness of the film containing the organic-inorganic hybrid layer, for example, 1%, 1.5%, 2%, 2.5%, 2.7%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%. When both surfaces of the film containing the organic-inorganic hybrid layer of the present invention are organic-inorganic hybrid surface layers, the thickness of the aforementioned organic-inorganic hybrid surface layer refers to the total thickness of the two organic-inorganic hybrid surface layers. In the organic-inorganic hybrid surface layer, the average particle size of the organic-inorganic hybrid nanoparticles can be 1 to 200nm, for example, 5nm, 10nm, 20nm, 50nm, 100nm, 120nm, 130nm, 150nm, 160nm.

[0064] In the present invention, the organic-inorganic hybrid nanoparticles contain organic components and inorganic components, wherein the inorganic components are formed by the reaction of the precursor with the reaction gas during the plasma chemical vapor deposition process; the organic components are formed by the plasma physical and chemical reaction of the precursor with the reaction gas and the polymer surface during the plasma chemical vapor deposition process, and the organic components retain the organic structural units of the original precursor or form new organic structural units. In the organic-inorganic hybrid nanoparticles, there is a physical and / or chemical connection between the inorganic component and the organic component.

[0065] The membrane containing an organic-inorganic hybrid layer of the present invention can be prepared by a regional combination atmospheric pressure plasma chemical vapor deposition method. In the present invention, the regional combination atmospheric pressure plasma chemical vapor deposition method includes: feeding a reaction gas and a precursor carried by a carrier gas into at least one plasma reactor without applying a voltage to generate at least one non-discharge area; feeding a discharge gas into at least one plasma reactor, discharging the discharge gas by a high voltage alternating current to generate at least one plasma area, feeding the reaction gas and the precursor carried by the carrier gas into the plasma area for reaction; allowing the porous substrate to first pass through at least one non-discharge area for adsorption, and then pass through at least one plasma area for deposition reaction, and the reaction product is deposited on the porous substrate to obtain a membrane containing an organic-inorganic hybrid layer. In the present invention, there is no plasma in the non-discharge area, and the porous substrate is adsorbed by the reaction gas and the precursor when passing through the non-discharge area. When the number of plasma areas is two or more, the two adjacent plasma areas can be continuous or discrete. One or more non-discharge areas can be set between two discrete adjacent plasma areas, so that after the porous substrate passes through the previous plasma area, it first passes through one or more non-discharge areas, and then passes through the next plasma area.

[0066] In some embodiments, the regional combined atmospheric pressure plasma chemical vapor deposition method includes: using high voltage alternating current to discharge the discharge gas to generate a plasma region, sending the reaction gas and the precursor or the precursor carried by the carrier gas into the plasma region for reaction, and the porous substrate successively passes through two or more continuous or discrete plasma regions for deposition reaction, and the reaction products are deposited on the porous substrate to obtain a film containing an organic-inorganic hybrid layer.

[0067] In the present invention, a continuous plasma region refers to two or more different plasma regions that are closely connected, but the reaction gas and / or precursor in each plasma region may be the same or different. A discrete plasma region refers to two or more independent plasma regions that are at a certain distance from each other, and the reaction gas and / or precursor in each discrete plasma region may be the same or different. Each independent and discrete region atmospheric pressure plasma chemical vapor deposition device has a gas sealing unit at both ends.

[0068] In the present invention, the gas pressure of each plasma region of the regional combined atmospheric pressure plasma chemical vapor deposition is near the atmospheric pressure, for example, in the range of 0.99 to 1.05 atmospheres. The regional combined atmospheric pressure plasma chemical vapor deposition can be carried out in a roll-to-roll manner, that is, when performing the regional combined atmospheric pressure plasma chemical vapor deposition, the rolled porous substrate can be unrolled and enter the frontmost plasma region, and then rewound after leaving the rearmost plasma region, thereby realizing roll-to-roll preparation of a membrane containing an organic-inorganic hybrid layer.

[0069] It can be understood that in the present invention, since the process of depositing the reaction products on the porous substrate by regional combined atmospheric pressure plasma chemical vapor deposition has almost no effect on the thickness of the porous substrate, the total thickness of the porous substrate layer and the transition layer in the membrane containing the organic-inorganic hybrid layer of the present invention is approximately equal to the thickness of the porous substrate as the raw material.

[0070] In the present invention, the number of plasma regions may be 1 to 5, such as 1, 2, 3, 4, or 5. The number of non-discharge regions may be 1 to 5, such as 1, 2, 3, 4, or 5.

[0071] In the present invention, the discharge gas may be one or both selected from argon and helium.

[0072] In the present invention, the precursor can be a gaseous, liquid or solid compound. The gaseous precursor can be directly fed into the plasma region, or fed into the plasma region by a carrier gas. The liquid precursor can be fed into the plasma region by bubbling or ultrasound of a carrier gas. The solid precursor can be dissolved in a solvent at a certain concentration and then fed into the plasma region by a carrier gas.

[0073] In the present invention, the precursor includes a first precursor. In some embodiments, the precursor is a first precursor.

[0074] The first precursor may be one or more compounds containing one or more elements selected from silicon, aluminum, titanium, zirconium, calcium, magnesium, zinc and barium and one or more elements selected from oxygen, carbon, nitrogen, hydrogen, sulfur, fluorine and chlorine. Examples of the first precursor that can be used include: organic silicon compounds, such as silane, polydimethylsiloxane (PDMS), hexamethyldisiloxane (HMDSO), octamethylcyclotetrasiloxane (D4), tetraethylcyclotetrasiloxane, dimethylsiloxane, tetraethylorthosilicate, vinyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, vinyltriethoxysilane and vinyltrimethoxysilane; titanium-containing compounds, such as n-butyl titanate, isobutyl titanate, etc.; aluminum-containing compounds, such as trimethylaluminum, aluminum acetate, aluminum hydroxide, aluminum isopropoxide, etc. In some preferred embodiments, the first precursor is an organosilicon compound, for example, the first precursor can be selected from one or more of hexamethyldisiloxane, octamethylcyclotetrasiloxane and vinyltriethoxysilane. More preferably, the first precursor is octamethylcyclotetrasiloxane.

[0075] In the present invention, the precursor preferably or optionally further comprises one or more lyophilic groups (such as -COOH, -OH, -COO, -OCO, -SO 3H, -SO 3 The second precursor is preferably a first precursor (e.g., a second precursor of a first type). The use of a second precursor is beneficial to increase the affinity of the deposited film to the electrolyte. The lyophilic group may be a hydroxyl group, a carboxyl group, an ester group, a sulfonic acid group, a sulfonic ester group, etc. In some embodiments, the precursor is composed of a first precursor and a second precursor. The second precursor may be one or more compounds selected from water, ethanol, acetic acid, acrylic acid, acrylate (e.g., methyl acrylate), tannic acid, sulfonic acid, and sulfonic ester. In some preferred embodiments, the second precursor is selected from one or more compounds selected from water, acrylic acid, tannic acid, methyl acrylate, and acetic acid.

[0076] In the present invention, precursors include inert precursors and active precursors. In this article, inert precursors refer to precursors that have not been activated, that is, the aforementioned compounds that can be used as precursors that have not been treated with high-energy particles. Active precursors (also called active gases) refer to substances formed by the activation of inert precursors by high-energy particles (such as electron beams, ion beams, pulsed lasers, radio frequencies, etc.).

[0077] In the present invention, unless otherwise specified, the precursor refers to an activated or inactivated (inert) first or second precursor.

[0078] In some embodiments, the above-mentioned inert precursor is converted into an active precursor with certain chemical activity by activation methods including but not limited to electron beam, ion beam, pulsed laser, radio frequency, etc. In some embodiments, the active precursor is introduced into the non-discharge area so that the active precursor gas is adsorbed on the porous substrate, or the active precursor is introduced into the plasma area so that the active precursor gas is adsorbed and deposited on the porous substrate, so as to improve the deposition efficiency and reduce the impact on the mechanical properties of the base film.

[0079] In some embodiments, the first precursor is introduced into at least one non-discharge region, and the first precursor and / or the second precursor are introduced into other non-discharge regions that are optionally or preferably present.

[0080] In some embodiments, the first precursor is introduced into at least one plasma region, and the first precursor and / or the second precursor are introduced into other plasma regions that are optionally or preferably present.

[0081] In some embodiments, in the regional combined atmospheric pressure plasma chemical vapor deposition of the present invention, before the porous substrate is passed through two or more continuous or discrete plasma reaction zones for deposition reaction, the porous substrate is first passed through one or more non-discharge zones, and precursors and / or reaction gases are introduced into the non-discharge zones without discharge, so that the precursors and / or reaction gases are adsorbed on the porous substrate. This is beneficial to improving the deposition efficiency, reducing the time required to deposit nanoparticles of the same thickness in the plasma zone, and reducing the impact on the mechanical properties of the base film.

[0082] In some embodiments, in the regional combined atmospheric pressure plasma chemical vapor deposition of the present invention, one or more non-discharge regions are set between two separate plasma reaction regions, and the porous substrate passes through the one or more non-discharge regions. Precursors and / or reaction gases are introduced into the non-discharge regions, but no discharge is performed, so that the precursors and / or reaction gases are adsorbed on the porous substrate. This is beneficial to improving the deposition efficiency, reducing the time required to deposit nanoparticles of the same thickness in the plasma region, and reducing the impact on the mechanical properties of the base film.

[0083] In the present invention, the time for the porous matrix to pass through each non-discharge area can be 1-60 seconds, for example, 2 seconds, 4 seconds, 8 seconds, 9 seconds, 10 seconds, 20 seconds, 30 seconds, 50 seconds, and 60 seconds.

[0084] In the present invention, the time for the porous matrix to pass through each plasma region can be 1-60 seconds, for example, 2 seconds, 4 seconds, 8 seconds, 9 seconds, 10 seconds, 20 seconds, 30 seconds, 50 seconds, and 60 seconds.

[0085] In some embodiments, the regional combined atmospheric pressure plasma chemical vapor deposition method includes: passing the porous substrate through a first non-discharge zone, loading an inert or active first precursor and a reaction gas but not discharging for adsorption; and then passing the porous substrate through a first plasma zone, loading an inert or active first precursor and a reaction gas for discharge deposition.

[0086] In some preferred embodiments, the regional combined atmospheric pressure plasma chemical vapor deposition method includes: passing the porous substrate through a non-discharge area, loading one or more precursors selected from the inert or active first precursor and the second precursor and the reaction gas for adsorption; then passing the porous substrate through a plasma area, loading the inert or active first precursor and the reaction gas for discharge deposition. In some preferred embodiments, after the porous substrate passes through a non-discharge area and a plasma area successively, the porous substrate can be passed through the second plasma area, and one or more precursors selected from the inert or active first precursor and the second precursor and the reaction gas are loaded for discharge deposition. In some preferred embodiments, a non-discharge area can be set between the first plasma area and the second plasma area, and the porous substrate passes through the non-discharge area, and one or more precursors selected from the inert or active first precursor and the second precursor and the reaction gas are loaded for adsorption. Preferably, the first precursor is an organosilicon compound, for example, the first precursor can be selected from one or more of hexamethyldisiloxane, octamethylcyclotetrasiloxane and vinyltriethoxysilane. Preferably, the second precursor is selected from one or more of water, acrylic acid, tannic acid, methyl acrylate and acetic acid.

[0087] In some preferred embodiments, the regional combined atmospheric pressure plasma chemical vapor deposition method includes: passing the porous substrate through a first non-discharge zone, loading an inert or active first precursor and a reaction gas but not discharging for adsorption; then passing the porous substrate through a first plasma zone, loading an inert or active first precursor and a reaction gas for discharge deposition; then passing the porous substrate through a second non-discharge zone, loading an inert or active first precursor and / or a second precursor and a reaction gas but not discharging for adsorption; then passing the porous substrate through a second plasma zone, loading an inert or active first precursor and / or a second precursor and a reaction gas for discharge deposition.

[0088] The precursor can be carried by a carrier gas into the plasma region and the non-discharge region. In the present invention, the carrier gas can be one or more selected from argon, helium, nitrogen and air.

[0089] In the present invention, usable reaction gases include, but are not limited to, one or more of oxygen, nitrogen, carbon dioxide and air.

[0090] In the present invention, when the precursor is fed into the plasma region or the non-discharge region, the carrier gas can be passed through the liquid precursor or the precursor solution, and the precursor is loaded on the carrier gas flow and enters the reactor by bubbling or ultrasound. The volume flow ratio of the carrier gas carrying the precursor to the reaction gas can be 1:30 to 600:1, for example, 1:10, 1:1, 10:1, 50:1, 100:1, 200:1, 300:1, 400:1, 500:1. In the carrier gas carrying the precursor, the volume concentration of the precursor can be 500 to 5000ppm, for example, 600ppm, 800ppm, 1000ppm, 1500ppm, 2000ppm, 2500ppm, 3000ppm, 3500ppm, 4000ppm, 4500ppm. The total flow rate of the carrier gas carrying the precursor and the reaction gas can be 1 to 30 SLM, for example, 2 SLM, 3 SLM, 4 SLM, 5 SLM, 6 SLM, 8 SLM, 10 SLM, 15 SLM, 20 SLM, 25 SLM.

[0091] In the present invention, the volume flow ratio of the reaction gas to the discharge gas may be 1:2 to 1:1000, for example, 1:2, 1:3, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200, 1:400, 1:500, 1:800, 1:1000.

[0092] In the present invention, the high voltage alternating current may be a sine or cosine waveform alternating current, and its frequency may be 10 to 300 kHz, for example, 15 kHz, 20 kHz, 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, 90 kHz, 100 kHz, 200 kHz, or 250 kHz.

[0093] In the present invention, the high voltage alternating current can also be an alternating current with a pulse waveform, that is, a high voltage pulse power supply is used. The pulse frequency can be 30 to 100kHz, such as 50kHz, 60kHz, 70kHz, 80kHz. The pulse width can be 5 to 1000ns, such as 10ns, 30ns, 70ns, 90ns, 300ns, 600ns, 700ns, 900ns. The pulse rising edge is preferably less than 50ns, such as 10ns, 20ns, 30ns, 40ns. The pulse duty ratio can be 1%-99%, such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%.

[0094] In the present invention, the peak voltage of the high voltage alternating current may be 500 to 30,000 V, such as 1,000 V, 1,500 V, 2,000 V, 3,000 V, 4,000 V, 5,000 V, 6,000 V, 7,000 V, 8,000 V, 9,000 V, 10,000 V, 18,000 V, 25,000 V. In the present invention, the high voltage alternating current refers to alternating current with a peak voltage ≥ 500 V.

[0095] In the present invention, a discharge gas is introduced into a plasma reactor, and a high voltage alternating current is used to discharge the discharge gas to generate plasma, thereby forming a plasma region. Plasma can be generated by dielectric barrier discharge, that is, the plasma reactor can be a dielectric barrier discharge plasma reactor. The structure of a dielectric barrier discharge plasma reactor is known. In some embodiments, the discharge parameters of the high voltage alternating current power supply of each plasma region are independently controlled, including power supply frequency, waveform, voltage, power, duty cycle, etc. In some embodiments, the discharge gas is discharged to generate plasma in some plasma regions, while other non-discharge regions are not discharged. In the present invention, a precursor and a reaction gas are introduced into a plasma reactor, but a high voltage alternating current is not applied, thereby generating a non-discharge region in which no plasma exists in the plasma reactor. The non-discharge region accepts adsorption of the precursor and the reaction gas, and the plasma region accepts adsorption and deposition of the reaction product.

[0096] The dielectric barrier discharge plasma reactor comprises a pair of electrodes. The pair of electrodes may be in the form of symmetrical electrodes (i.e., the two electrodes are the same) or asymmetrical electrodes (i.e., the two electrodes are different). The pair of electrodes may be one of comb electrodes, showerhead electrodes, coplanar electrodes, flat electrodes or rod electrodes, or a combination of two.

[0097] In some preferred embodiments, the regional combination atmospheric pressure plasma chemical vapor deposition includes: allowing an inert or active first precursor and a reactive gas to enter a non-discharge region; then allowing the inert or active first precursor and the reactive gas to enter a first plasma region; then allowing the inert or active first precursor and the reactive gas to enter a non-discharge region; and finally allowing the inert or active first precursor, the reactive gas and the optional or preferred second precursor to enter a second plasma region. The non-discharge region does not discharge, the first plasma region uses a sinusoidal high-frequency high-voltage power supply to discharge, and the second plasma combination region uses a high-frequency high-voltage pulse power supply to discharge. In these embodiments, compared with using an inert first precursor in only one plasma region to discharge and deposit using a single power source, the present invention introduces different inert or active precursors and reaction gases into the non-discharge region and multiple plasma regions, and independently controls the discharge power source and discharge characteristics of each region, so that the inert or active first precursor and reaction gas enter the non-discharge region for only adsorption, the inert or active first precursor and reaction gas enter the first plasma region for discharge deposition, and the inert or active first precursor, reaction gas and the optional or preferred second precursor enter the second plasma region for discharge deposition, which is conducive to making the film of the present invention contain a multi-layer physical and chemical structure, shortening the substrate surface plasma reaction deposition time, so that the film of the present invention can contain more polar Si-O, Si-OH, Si-O-Si, Si-C, and one or more organic functional groups selected from OC=O, C-OH, COOH, CO and C=O, which is conducive to improving the porosity and the lyophilic properties, reducing the decline in mechanical properties, so that the film of the present invention can give the battery better performance when used as a battery separator.

[0098] In the present invention, atmospheric pressure dielectric barrier discharge, as well as different discharge power supplies and discharge parameters, electrode combinations, precursor activation, inert or active precursors, reaction gas and carrier gas types, gas introduction methods and flow ratios are adopted, so that online real-time synthesis of nanoparticles and porous medium deposition can be achieved, and particle size, pore size, porosity, surface groups, etc. can be regulated. There is no problem of agglomeration and secondary dispersion of large nanoparticles, and there is no need to add dispersants, solvents, and binders. The deposition process has a fast rate, low energy consumption, and little pollution. It is integrated with the existing diaphragm production line, and is green and environmentally friendly dry preparation, which is feasible for industrial application.

[0099] The membrane containing the organic-inorganic hybrid layer of the present invention can be applied to sensors, energy storage materials or devices, energy conversion materials or devices, optical materials and devices, optoelectronic materials and devices, water treatment materials or devices, drug delivery materials or devices, drug separation materials or devices, biological fluid separation materials or devices, blood separation materials or devices, etc.

[0100] The membrane containing an organic-inorganic hybrid layer of the present invention has good hydrophilicity and good affinity with the main components of the electrolyte of batteries such as lithium iron phosphate batteries, ternary lithium ion batteries, and sodium sulfur batteries. The membrane containing an organic-inorganic hybrid layer of the present invention does not have added components such as binders and dispersants, and the organic-inorganic hybrid nanoparticles have good adhesion properties to the porous matrix (such as an organic polymer battery separator), and are not easy to fall off during processing and use. The membrane containing an organic-inorganic hybrid layer of the present invention provides a support function when the separator fiber collapses due to heat, and the heat-resistant shrinkage performance is improved, meeting the safety requirements of the processing and use process. The membrane containing an organic-inorganic hybrid layer of the present invention has the same basic properties as the base membrane, such as the same surface density, thickness and air permeability. The membrane containing an organic-inorganic hybrid layer of the present invention contains chemical groups, which is conducive to the improvement of porosity, and has an improved liquid absorption rate and saturation rate. Using the membrane containing an organic-inorganic hybrid layer of the present invention as a separator can reduce the impedance of the battery, improve the rate cycle characteristics, increase the capacity, improve the low-temperature rate characteristics, and reduce the formation and filling time of the battery production process.

[0101] The present invention has the following advantages:

[0102] (1) Compared with the wet coating method, the regional combined atmospheric pressure plasma chemical vapor deposition method of the present invention realizes dry real-time synthetic coating without the problem of nanomaterial agglomeration. The obtained thin film coating has a small thickness, low material consumption, short coating formation time, no need for drying, no waste liquid discharge, energy saving and environmental protection, and low cost.

[0103] (2) Compared with vacuum physical and chemical deposition methods, the regional combined atmospheric pressure plasma chemical vapor deposition method of the present invention realizes real-time online, does not require vacuum, is integrated with existing production lines, has industrial feasibility, and the deposit is composed of nanoparticles with improved porosity, large specific surface area, and high liquid absorption rate.

[0104] (3) Compared with the existing atmospheric pressure gas phase chemical reaction polymerization deposition method, the regional combination atmospheric pressure plasma chemical vapor deposition method of the present invention realizes different plasma discharge characteristics in different regions, couples more electrophilic electrolytes and organic functional groups that are conducive to lithium ion transmission, and uses inert / active precursors to be adsorbed in non-discharge areas or adsorbed and deposited in plasma areas. In addition to being able to contain more polar Si-O, Si-OH, Si-O-Si, Si-C, it can also contain one or more organic functional groups selected from OC=O, C-OH, COOH, CO and C=O. The discharge deposition time is greatly reduced, and the deposition efficiency and base film operation speed are greatly improved. A multi-layer combination structure is realized, which includes a porous substrate layer, an organic-inorganic hybrid nanoparticle transition layer and an organic-inorganic hybrid nanoparticle surface layer, and greatly reduces the damage caused by the plasma deposition process to the original mechanical properties of the porous substrate.

[0105] (4) Using the membrane containing the organic-inorganic hybrid nanoparticle layer of the present invention as a separator for a secondary battery can improve the lyophilicity, thermal shrinkage, liquid absorption rate, liquid saturation rate, and ion conductivity of the separator, reduce the electrolyte formation and filling processing time of the secondary battery using the separator, and improve the low-temperature rate characteristics, cycle rate characteristics, and battery energy density of the secondary battery using the separator. At the same time, the original basic properties of the separator, such as surface density, thickness, air permeability, and mechanical properties, are almost unchanged.

[0106] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0107] The preparation method of the basic electrolyte used in the embodiments and comparative examples is as follows: LiPF 6 The basic electrolyte is prepared by dissolving in a mixture of dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylene carbonate (EC) and ethyl acetate (EA) in a mass ratio of 1:1:1:0.3. 6 The concentration is 1mol / L.

[0108] The polyethylene (PE) diaphragm and alumina coating diaphragm used in the examples and comparative examples were purchased from Shanghai Enjie New Materials Co., Ltd.

[0109] The test results in the embodiments and comparative examples are shown in Table 1.

[0110] Embodiment 1

[0111] The precursor hexamethyldisiloxane (HMDSO) and the reaction gas oxygen were introduced into the dielectric barrier discharge plasma reactor 1 and the reactor 2 by bubbling, with a total flow rate of 2 SLM of Ar gas. 2The volume flow ratio is 100 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 870ppm. No voltage is applied to reactor 1. Discharge gas Ar gas is introduced into reactor 2, and the volume flow ratio of the reaction gas to the discharge gas is 1 / 3. Reactor 2 applies a high-frequency high-voltage power supply with a sinusoidal waveform, the discharge frequency is 20kHz, and the peak voltage is 5000V. Both reactor 1 and reactor 2 use a combination of rod electrodes and flat electrodes. At normal temperature and pressure, a PE diaphragm with a thickness of 12μm as a porous matrix is ​​passed through reactor 1 and reactor 2 successively. The time for the diaphragm to pass through reactor 1 is 30 seconds, and the time for passing through reactor 2 is 45 seconds. Plasma polymerization chemical reaction deposition occurs on the upper surface of the diaphragm to obtain a diaphragm having a three-layer structure combination of a porous matrix layer, an organic-inorganic hybrid transition layer, and an organic-inorganic hybrid surface layer.

[0112] The ratio of the surface layer thickness to the total thickness of the diaphragm prepared in this embodiment is H s / H 0 = 2%, the average particle size of the organic-inorganic hybrid nanoparticles in the surface layer is 118nm. The ratio of the transition layer thickness to the total thickness of the diaphragm is H t / H 0 = 21%, the average particle size of the organic-inorganic hybrid nanoparticles in the transition layer is 38nm. The diaphragm prepared in this embodiment is completely infiltrated with the basic electrolyte, and the area diffusion rate (cm 2 / min) is 1.5 times the diffusion rate of the commercial alumina coating diaphragm, and the liquid absorption rate is 104%. Compared with the thermal shrinkage rate of the PE diaphragm as the raw material, the thermal shrinkage rate of the diaphragm prepared in this embodiment at 120°C and 1h is reduced by 80% (TD) and 78% (MD), the charge transfer impedance is reduced by 43%, and the tensile strength is reduced by 30% (TD) and 20% (MD).

[0113] Example 2

[0114] The precursor hexamethyldisiloxane (HMDSO) and the reaction gas oxygen were introduced into the dielectric barrier discharge plasma reactor 1 and the reactor 2 respectively by bubbling, with a total flow rate of 2 SLM and 6 SLM of Ar gas. 2 The volume flow ratio of the precursor is 100 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 870 ppm. By bubbling, the Ar gas loaded with the precursor acrylic acid (AA) and the reaction gas oxygen with a total flow rate of 2 SLM and 6 SLM were introduced into the dielectric barrier discharge plasma reactor 3 and the reactor 4, respectively. The Ar / O 2The volume flow ratio is 100 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 870ppm. No voltage is applied to reactor 1 and reactor 3. Discharge gas Ar gas is introduced into reactors 2 and 4, and the volume flow ratio of the reaction gas to the discharge gas is 1 / 40. Reactors 2 and 4 apply a high-frequency high-voltage power supply with a sinusoidal waveform, the discharge frequency is 20kHz, and the peak voltage is 5000V. Reactors 1-4 all use a combination of rod electrodes and flat electrodes. At room temperature and pressure, a PE diaphragm with a thickness of 12μm as a porous matrix is ​​passed through reactor 1, reactor 2, reactor 3 and reactor 4 in turn, and the time is 15 seconds, 25 seconds, 15 seconds and 25 seconds respectively. Plasma polymerization chemical reaction deposition occurs on the upper surface of the diaphragm to obtain a diaphragm having a three-layer structure combination of a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer.

[0115] The ratio of the surface layer thickness to the total thickness of the diaphragm prepared in this embodiment is H s / H 0 = 2.8%, the average particle size of the organic-inorganic hybrid nanoparticles in the surface layer is 108nm. The ratio of the transition layer thickness to the total thickness of the diaphragm is H t / H 0 =38%, the average particle size of the organic-inorganic hybrid nanoparticles in the transition layer is 17nm. The diaphragm prepared in this embodiment is completely infiltrated with the basic electrolyte, and the area diffusion rate (cm 2 / min) is 2.6 times the diffusion rate of the commercial alumina coating diaphragm, and the liquid absorption rate is 116%. Compared with the thermal shrinkage rate of the PE diaphragm as the raw material, the diaphragm prepared in this embodiment has a 120°C, 1h thermal shrinkage rate reduction rate of 82% (TD) and 80% (MD), a charge transfer impedance reduction rate of 59%, and a tensile strength reduction rate of 30% (TD) and 21% (MD).

[0116] Example 3

[0117] The Ar gas-loaded precursor hexamethyldisiloxane was activated by radio frequency discharge through bubbling to obtain activated hexamethyldisiloxane (AC-HMDSO). Then, the Ar gas-loaded precursor AC-HMDSO and the reaction gas oxygen with a total flow rate of 3 SLM and 6 SLM were introduced into the dielectric barrier discharge plasma reactor 1 and reactor 2, respectively. The Ar / O 2 The volume flow ratio of the precursor is 500 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 1300ppm. By bubbling, the Ar gas loaded with the precursor AC-HMDSO and the reaction gas oxygen with a total flow rate of 3SLM and 6SLM were introduced into the dielectric barrier discharge plasma reactor 3 and reactor 4, respectively. The Ar / O 2The volume flow ratio of the precursor is 500 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 1300ppm. No voltage is applied to reactor 1 and reactor 3. Discharge gas Ar gas is introduced into reactors 2 and 4, and the volume flow ratio of the reaction gas to the discharge gas is 1 / 20. Reactor 2 and reactor 4 apply a high-frequency high-voltage power supply with a sinusoidal waveform, the discharge frequency is 70kHz, and the peak voltages are 5000V and 3000V, respectively. Reactor 2 uses a combination of rod electrodes and flat electrodes, and reactor 4 uses coplanar electrodes. At room temperature and pressure, a PE diaphragm with a thickness of 9μm as a porous matrix passes through reactor 1, reactor 2, reactor 3 and reactor 4 in turn, and the time is 20 seconds, 15 seconds, 20 seconds and 10 seconds, respectively. Plasma polymerization chemical reaction deposition occurs on the upper surface of the diaphragm to obtain a diaphragm with a three-layer structure consisting of a porous matrix layer, an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer.

[0118] The ratio of the surface layer thickness to the total thickness of the diaphragm prepared in this embodiment is H s / H 0 =5%, the average particle size of the organic-inorganic hybrid nanoparticles in the surface layer is 129nm. The ratio of the transition layer thickness to the total thickness of the diaphragm is H t / H 0 =41%, the average particle size of the organic-inorganic hybrid nanoparticles in the transition layer is 28nm. The diaphragm prepared in this embodiment is completely infiltrated with the basic electrolyte, and the area diffusion rate (cm 2 / min) is 3 times the diffusion rate of the commercial alumina coating diaphragm, and the liquid absorption rate is 118%. Compared with the thermal shrinkage rate of the PE diaphragm as the raw material, the thermal shrinkage rate of the diaphragm prepared in this embodiment at 120°C and 1h is reduced by 85% (TD) and 80% (MD), the charge transfer impedance is reduced by 47%, and the tensile strength is reduced by 20% (TD) and 17% (MD).

[0119] Example 4

[0120] The Ar gas-loaded precursor octamethylcyclotetrasiloxane (D4) was activated by radio frequency discharge to obtain activated octamethylcyclotetrasiloxane (AC-D4). Then, the Ar gas-loaded precursor AC-D4 and the reaction gas oxygen with a total flow rate of 2 SLM and 6 SLM were introduced into the dielectric barrier discharge plasma reactor 1 and reactor 2, respectively. The Ar / O 2 The volume flow ratio of the precursor was 420 / 1 and 560 / 1 respectively, and the volume concentration of the precursor in the Ar gas loaded with the precursor was 1600 ppm. The Ar gas loaded with the precursor AC-D4 and the reaction gas oxygen with a total flow rate of 2 SLM and 6 SLM were introduced into the dielectric barrier discharge plasma reactor 3 and the reactor 4 respectively. 2The volume flow ratios are 420 / 1 and 560 / 1 respectively, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 1600ppm. No voltage is applied to reactor 1 and reactor 3. Discharge gas Ar gas is introduced into reactors 2 and 4, and the volume flow ratio of the reaction gas to the discharge gas is 1 / 50. A pulsed high-voltage power supply is applied to reactor 2 and reactor 4, with a pulse frequency of 70kHz, a pulse width of 80ns, a pulse rising edge of 20ns, a pulse duty cycle of 29%, and a peak voltage of 3000V. Reactor 2 and reactor 4 both use a combination of coplanar electrodes with opposite installation directions. At normal temperature and pressure, a PE diaphragm with a thickness of 7μm, which serves as a porous matrix, is passed through the lower surfaces of reactor 1, reactor 2 and reactor 3, and the upper surface of reactor 4 in succession, with the time being 18 seconds, 4 seconds, 18 seconds and 4 seconds respectively. Plasma polymerization chemical reaction deposition occurs on the upper and lower surfaces of the diaphragm respectively, so as to obtain a diaphragm having a porous matrix layer, an organic-inorganic hybrid transition layer on both the upper and lower surfaces, and an organic-inorganic hybrid surface layer structure combination.

[0121] The ratio of the sum of the thickness of the upper and lower surface layers of the diaphragm prepared in this embodiment to the total thickness of the diaphragm is H. s / H 0 = 6%, the average particle size of the organic-inorganic hybrid nanoparticles in the surface layer is 95nm. The ratio of the sum of the thickness of the upper and lower transition layers to the total thickness of the diaphragm is H t / H 0 =70%, the average particle size of the organic-inorganic hybrid nanoparticles in the transition layer is 25nm. The diaphragm prepared in this embodiment is completely infiltrated with the basic electrolyte, and the area diffusion rate (cm 2 / min) is 3.6 times the diffusion rate of the commercial alumina coating diaphragm, and the liquid absorption rate is 127%. Compared with the thermal shrinkage rate of the PE diaphragm as the raw material, the diaphragm prepared in this embodiment has a 120°C, 1h thermal shrinkage rate reduction rate of 87% (TD) and 83% (MD), a charge transfer impedance reduction rate of 72%, and a tensile strength reduction rate of 11% (TD) and 8% (MD).

[0122] Comparative Example 1

[0123] The precursor hexamethyldisiloxane (HMDSO) and the reaction gas oxygen were introduced into the dielectric barrier discharge plasma reactor 1 by bubbling with Ar gas at a flow rate of 6 SLM. 2The volume flow ratio is 100 / 1, and the volume concentration of the precursor in the Ar gas loaded with the precursor is 870ppm. The discharge gas He gas is introduced into the reactor 1, and the volume flow ratio of the reaction gas to the discharge gas is 1 / 10. The reactor 1 applies a high-frequency high-voltage power supply with a sinusoidal waveform, the discharge frequency is 20kHz, and the peak voltage is 5000V. Reactor 1 adopts a combination of rod electrodes and flat electrodes. At normal temperature and pressure, a PE diaphragm with a thickness of 12μm as a porous matrix is ​​passed through the reactor 1, and the time for the diaphragm to pass through the reactor 1 is 60 seconds. Plasma polymerization chemical reaction deposition occurs on the upper surface of the diaphragm to obtain a diaphragm having a three-layer structure combination of a porous matrix layer, an organic-inorganic hybrid transition layer, and an organic-inorganic hybrid surface layer.

[0124] The ratio of the surface layer thickness to the total thickness of the diaphragm prepared in this comparative example is H s / H 0 =2.1%, the average particle size of the organic-inorganic hybrid nanoparticles in the surface layer is 125nm. The ratio of the transition layer thickness to the total thickness of the diaphragm is H t / H 0 =21.5%, the average particle size of the organic-inorganic hybrid nanoparticles in the transition layer is 46nm. The diaphragm prepared in this comparative example is completely infiltrated with the basic electrolyte, and the area diffusion rate (cm 2 / min) is 1.1 times the diffusion rate of the commercial alumina coated diaphragm, and the liquid absorption rate is 102%. Compared with the thermal shrinkage rate of the PE diaphragm as the raw material, the diaphragm prepared in this comparative example has a thermal shrinkage rate reduction rate of 78% (TD) and 70% (MD) at 120°C and 1h, a charge transfer impedance reduction rate of 41%, and a tensile strength reduction rate of 42% (TD) and 30% (MD).

[0125] Test Case

[0126] The present invention adopts the following performance testing method:

[0127] (1) Total film thickness, transition layer thickness and surface layer thickness

[0128] Scanning electron microscopy (SEM) generates secondary electrons by bombarding the sample surface with a high-energy electron beam, and displays the surface morphology of the sample by collecting feedback electron signals. Using field emission scanning electron microscopy, the cross-section and surface morphology of the diaphragm are observed by making cross-section and surface samples of the diaphragm. Combined with XPS / EDS, the distribution of deposited elements silicon and oxygen in the cross-section and surface is calculated, thereby calculating the total thickness of the film (H 0 ), transition layer thickness (H t ), surface layer thickness (H s ), the ratio of transition layer thickness to total thickness (H t / H 0 ), and the ratio of the surface layer thickness to the total thickness (Hs / H 0 ).

[0129] (2) Average particle size of organic-inorganic hybrid nanoparticles

[0130] A field emission scanning electron microscope was used to prepare membrane cross-section and surface samples, observe the membrane cross-section and surface morphology, and statistically calculate the average particle size of the nanoparticles through image recognition software.

[0131] (3) Area diffusion rate (lyophilicity)

[0132] The lyophilicity of the membrane is tested by the diffusion rate of the electrolyte. 6 Dissolved in a mixture of DMC, DEC, EC and EA in a mass ratio of 1:1:1:0.3 to form a basic electrolyte. LiPF 6 The concentration is 1 mol / L, and the color-developing dye methylene orange is added. The membrane is laid flat on the test bench, and 5 μL of electrolyte is dripped on the surface of the membrane through computer operation. The surface wetting of the electrolyte is observed and the contact angle of the electrolyte is measured. Complete wetting means that the contact angle is 0 degrees; at the same time, the change of the diffusion image over time is recorded, and the area diffusion rate (cm 2 / min).

[0133] (4) Liquid absorption rate

[0134] The diaphragm was immersed in n-butanol solution for 6 hours, and the mass of the diaphragm before and after absorbing liquid was weighed to obtain the mass of the absorbed liquid. The ratio of the mass of the absorbed liquid to the mass of the diaphragm was the liquid absorption rate.

[0135] Liquid absorption rate (%) = absorbed liquid mass / diaphragm mass * 100%

[0136] (5) Thermal shrinkage

[0137] Cut the diaphragm into 4×4cm 2 The membrane is then placed in a blast drying oven and the temperature is set to 120°C. It is heated for one hour. The dimensions of the membrane in the transverse (TD) and longitudinal (MD) directions before and after heating are compared. Based on the heat shrinkage rate, the heat shrinkage reduction rate is calculated. The results are shown in Table 1.

[0138] Thermal shrinkage rate (%) = (dimension of the diaphragm in a certain direction before heating - dimension of the diaphragm in the same direction after heating) / dimension of the diaphragm in the same direction before heating * 100%

[0139] Thermal shrinkage reduction rate (%) = (thermal shrinkage of the diaphragm in a certain direction before deposition - thermal shrinkage of the diaphragm in the same direction after deposition) / thermal shrinkage of the diaphragm in the same direction before deposition * 100%.

[0140] (6) AC impedance

[0141] The LiFePO 4 / Li battery impedance test, a small amplitude low frequency sinusoidal voltage is superimposed on the external DC voltage, and acted on the electrolytic cell together. Before the test, the battery has been standing for a certain period of time, and the battery voltage is basically unchanged. Using a three-electrode system, LiFePO 4 The electrode is the working electrode, the reference electrode and the auxiliary electrode are Li sheets, the excitation signal is a sinusoidal AC voltage with an amplitude of 5mV, and the test frequency range is 10 -3 -10 5 Hz, test the EIS spectrum of the diaphragm before and after charge and discharge, fit the results with Zview software, test the AC impedance of the electrodes in the electrolytic cell, and calculate the charge transfer impedance.

[0142] (7) Tensile strength

[0143] The membrane was clamped by a biaxial tensile tester. The membrane size was 20×60 mm. The initial spacing was 30 mm. Tension was applied along the membrane transverse direction (TD) or longitudinal direction (MD) at a speed of 5 mm / min until the membrane broke. The force was recorded and compared with the cross-sectional area to obtain the tensile strength. The tensile strength of the membrane before and after deposition was compared.

[0144] Tensile strength reduction rate (%) = (tensile strength of the diaphragm in a certain direction before deposition - tensile strength of the diaphragm in the same direction after deposition) / tensile strength of the diaphragm in the same direction before deposition * 100%

[0145] Table 1: Performance test results of the diaphragms of Examples 1-4 and Comparative Example 1

[0146]

Claims

1. A membrane comprising an organic-inorganic hybrid layer, It is characterized in that The membrane containing the organic-inorganic hybrid layer comprises a porous matrix layer and an organic-inorganic hybrid transition layer and an organic-inorganic hybrid surface layer located on one side or both sides of the porous matrix layer, wherein the organic-inorganic hybrid transition layer is located between the porous matrix layer and the organic-inorganic hybrid surface layer; The porous matrix layer contains fibers and does not contain organic-inorganic hybrid nanoparticles; The organic-inorganic hybrid transition layer comprises fibers and organic-inorganic hybrid nanoparticles; The organic-inorganic hybrid surface layer comprises organic-inorganic hybrid nanoparticles but does not comprise fibers; The total thickness of the film containing the organic-inorganic hybrid layer is 1 to 30 μm; The thickness of the organic-inorganic hybrid transition layer is 1% to 80% of the total thickness of the film containing the organic-inorganic hybrid layer, and the average particle size of the organic-inorganic hybrid nanoparticles in the organic-inorganic hybrid transition layer is 1 to 50 nm; The thickness of the organic-inorganic hybrid surface layer is 0.8% to 6% of the total thickness of the film containing the organic-inorganic hybrid layer, and the average particle size of the organic-inorganic hybrid nanoparticles in the organic-inorganic hybrid surface layer is 1 to 200 nm.

2. The film containing an organic-inorganic hybrid layer according to claim 1, It is characterized in that The material of the fiber is selected from one or more of synthetic fibers and natural fibers; preferably, the synthetic fiber is selected from one or more of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide and polyamide.

3. The film containing an organic-inorganic hybrid layer according to claim 1, It is characterized in that The membrane containing the organic-inorganic hybrid layer is prepared by plasma chemical vapor deposition reaction between a precursor and a reaction gas inside and on the surface of a porous matrix.

4. The film containing the organic-inorganic hybrid layer according to claim 3, It is characterized in that The precursor comprises a first precursor, wherein the first precursor is one or more compounds containing one or more elements selected from silicon, aluminum, titanium, zirconium, calcium, magnesium, zinc and barium and one or more elements selected from oxygen, carbon, nitrogen, hydrogen, sulfur, fluorine and chlorine, or their active gases, wherein the active gases are substances transformed from the compounds by the action of high-energy particles; preferably, the first precursor is one or more organosilicon compounds or their active gases; preferably, the organosilicon compounds are selected from silane, polydimethylsiloxane, hexamethyldisiloxane, octamethylcyclotetrasiloxane, tetraethylcyclotetrasiloxane, dimethylsiloxane, orthosilicic acid One or more of ethyl ester, vinyl triethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-methacryloxypropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-(β-aminoethyl)-γ-aminopropyl trimethoxysilane, vinyl triethoxysilane and vinyl trimethoxysilane; preferably, the precursor further comprises a second precursor, and the second precursor is one or more compounds selected from water, ethanol, acetic acid, acrylic acid, acrylic ester, tannic acid, sulfonic acid and sulfonic ester or their active gases, and the active gas is a substance converted by the action of high-energy particles on the compound; The reaction gas includes one or more of oxygen, nitrogen, carbon dioxide and air.

5. A method for preparing a film containing an organic-inorganic hybrid layer according to any one of claims 1 to 4, It is characterized in that The method is a regional combined atmospheric pressure plasma chemical vapor deposition method, which comprises: feeding a reaction gas and a precursor carried by a carrier gas into at least one plasma reactor without applying a voltage to generate at least one non-discharge area; feeding a discharge gas into at least one plasma reactor, causing the discharge gas to discharge by high voltage alternating current to generate at least one plasma area, feeding the reaction gas and the precursor carried by the carrier gas into the plasma area for reaction; allowing a porous substrate to first pass through at least one non-discharge area for adsorption, and then pass through at least one plasma area for deposition reaction, wherein the reaction product is deposited on the porous substrate to obtain the film containing the organic-inorganic hybrid layer.

6. The method according to claim 5, It is characterized in that The method has one or more of the following features: In each plasma region, the discharge gas is one or two selected from argon and helium; In each plasma region, the carrier gas is one or more selected from argon, helium, nitrogen and air; The time for the porous substrate to pass through each plasma region is 1 to 60 seconds; The number of the plasma regions is 1 to 5, for example, 1 to 3, 1 to 2; In each plasma region, the volume flow ratio of the carrier gas carrying the precursor to the reaction gas is 1:30 to 600:1; In each plasma region, the volume concentration of the precursor in the carrier gas carrying the precursor is 500-5000 ppm; In each plasma region, the total flow rate of the carrier gas carrying the precursor and the reaction gas is 1 to 30 SLM respectively; In each plasma region, the volume flow ratio of the reaction gas to the discharge gas may be 1:2 to 1:1000; In each plasma region, the peak voltage of the high voltage alternating current is 500 to 30,000 V; In each plasma region, the high voltage alternating current is a sine waveform, a cosine waveform or a pulse waveform alternating current, the frequency of the sine waveform and the cosine waveform alternating current is 10 to 300 kHz, the pulse frequency of the pulse waveform alternating current is 30 to 100 kHz, the pulse width is 5 to 1000 ns, the pulse rising edge is less than 50 ns, and the pulse duty cycle is 1% to 99%; The plasma is generated by dielectric barrier discharge.

7. The method according to claim 5, It is characterized in that The method has one or more of the following features: In each non-discharge region, the carrier gas is one or more selected from argon, helium, nitrogen and air; The time for the porous matrix to pass through each non-discharge area is 1 to 60 seconds; The number of the non-discharge areas is 1 to 5, for example, 1 to 3, 1 to 2; In each non-discharge area, the volume flow ratio of the carrier gas carrying the precursor to the reaction gas is 1:30 to 600:1; In each non-discharge region, the volume concentration of the precursor in the carrier gas carrying the precursor is 500-5000 ppm; In each non-discharge area, the total flow rate of the carrier gas carrying the precursor and the reaction gas is 1 to 30 SLM.

8. The method according to claim 5, It is characterized in that The number of plasma regions is at least two, and at least one or more non-discharge regions are respectively arranged before the first plasma region and between each two adjacent plasma regions, so that the porous substrate passes through one or more non-discharge regions before passing through each plasma region; Preferably, the number of non-discharge regions is two and the number of plasma regions is two, so that the porous substrate passes through the first non-discharge region, and the first precursor and the reaction gas are loaded but not discharged for adsorption; then the porous substrate passes through the first plasma region, and the first precursor and the reaction gas are loaded for discharge deposition; then the porous substrate passes through the second non-discharge region, and the first precursor and / or the second precursor and the reaction gas are loaded but not discharged for adsorption; then the porous substrate passes through the second plasma region, and the first precursor and / or the second precursor and the reaction gas are loaded for discharge deposition.

9. A production system for preparing a membrane containing an organic-inorganic hybrid layer as claimed in any one of claims 1 to 4 or for implementing a method as claimed in any one of claims 5 to 8, It is characterized in that The production system includes two or more plasma reactors; Preferably, the plasma reactor is a dielectric barrier plasma reactor; preferably, the electrodes of the dielectric barrier plasma reactor are selected from one or more of comb electrodes, showerhead electrodes, coplanar electrodes, flat plate electrodes and rod electrodes.

10. Use of the membrane containing an organic-inorganic hybrid layer according to any one of claims 1 to 4 or the membrane containing an organic-inorganic hybrid layer prepared by the method according to any one of claims 5 to 8 in water treatment materials or devices, drug delivery materials or devices, drug separation materials or devices, biological fluid separation materials or devices, blood separation materials or devices, sensors, energy storage materials or devices, energy conversion materials or devices, drug delivery materials or devices, optical materials or devices, or optoelectronic materials or devices.

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