CN105064007B - PI‑SiO2PTFE ternary nanos are combined many curved hole membrane materials and its preparation method and application - Google Patents

Abstract

The invention discloses a nanocomposite multi-porous membrane material, which uses polyimide (PI) nanofiber non-woven fabric as a base material, and the pores of the base material are filled with composite nanoparticles; it is characterized in that: the composite The nanoparticles are composed of polytetrafluoroethylene nanospheres (PTFE-NP) and silicon dioxide nanoparticles (SiO ₂ -NP) mixed in a weight ratio of (7-12)/(8-13). The nanocomposite multi-porous membrane material provided by the invention has high temperature resistance, moderate porosity, moderate areal density, good ion transport and excellent mechanical properties, and can overcome pure polyimide when used in lithium ion batteries. The nanofiber diaphragm causes the problem of micro-short circuit of the battery due to too high porosity; it can solve the serious problem of thermal runaway of the power lithium-ion battery due to mechanical collision.

Description

PI-SiO2-PTFE ternary nanocomposite multi-porous membrane material and its preparation method and application

technical field

The invention belongs to the field of battery diaphragms and relates to a multi-porous membrane material, in particular to an organic/inorganic ternary nanocomposite material, a preparation method thereof and an application as a battery diaphragm.

Background technique

As the power battery of new energy vehicles, lithium-ion batteries have been developed rapidly and will become an indispensable daily necessities for human beings. However, since the currently used lithium battery separator is a polyolefin porous membrane material with poor temperature resistance, at a higher temperature, or in the case of overcharging, overdischarging and mechanical damage, lithium-ion batteries are prone to smoke, Fire, even explosion and other hidden dangers that endanger the safety of users. Therefore, improving the safety of lithium-ion batteries is the key to promoting the application of lithium-ion batteries in automotive power and other fields.

For the safety of lithium batteries, a high-porosity electrospun PI nanofiber battery separator has been developed by taking advantage of the high heat resistance of PI materials. This high-porosity PI nanofiber separator does not shrink at a high temperature of 300°C, and has the characteristics of overcharge and overdischarge resistance, high rate performance and high cycle performance, which greatly improves the electrochemical performance of lithium-ion batteries. However, since this electrospun nanofiber separator is a non-woven fabric stacked by fibers, it has too high porosity and too large surface pore size, resulting in a low charge retention rate of the battery and frequent micro-short circuits. Especially when the thickness of the battery separator is low, such as below 30 microns, the probability of this situation is quite high. Therefore, it is very necessary to create a new high-temperature-resistant and high-safety lithium-ion battery separator with lower porosity and smaller surface pore size.

Contents of the invention

One of the objectives of the present invention is to provide a temperature-resistant, high-safety multi-cable porous membrane material with lower porosity and smaller surface pore size.

The second object of the present invention is to provide a method for preparing the tortuous porous membrane material.

The third object of the present invention is to provide the application of the porous membrane material in battery separators.

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

First of all, a nanocomposite multi-porous membrane material is provided, which uses polyimide (PI) nanofiber nonwovens as a base material, and composite nanoparticles are filled in the pores of the base material; Vinyl fluoride nanospheres (PTFE-NP) and silicon dioxide nanoparticles (SiO ₂ -NP) are mixed in a weight ratio of (7-12)/(8-13).

In the preferred nanocomposite porous membrane material of the present invention, the composite nanoparticles are composed of PTFE-NP and SiO ₂ -NP mixed in a weight ratio of (30-42)/(38-50); the most preferred The weight ratio of PTFE-NP and SiO ₂ -NP includes 42/38, 30/50 or 36/44.

In the preferred nanocomposite porous membrane material of the present invention, the diameter of the PTFE-NP is preferably between 80-300nm; the diameter of the SiO ₂ -NP is preferably between 50-800nm.

The ratio of the PTFE-NP and SiO ₂ -NP to the total weight of the nanocomposite porous membrane material is preferably between 30-60%.

The thickness of the preferred nanocomposite porous membrane material in the present invention is between 10-40 μm.

The preferred nanocomposite porous membrane material of the present invention is obtained by coating or impregnating PI nanofibers with a water-based mixed suspension containing PTFE-NP and SiO ₂ -NP in a weight ratio of (7-12)/(8-13) The non-woven fabric is obtained by making the suspension infiltrate and fill the pores of the PI nanofiber non-woven fabric, and then drying at a high temperature of 100-200°C.

The water-based mixed suspension preferably further contains 1.0% to 2.5% of binder and 0.05% to 0.15% of dispersant accounting for the total weight of the suspension.

The binder is preferably polyacrylate, more preferably butyl acrylate-isooctyl acrylate copolymer.

The dispersant is preferably ammonium polyacrylate.

The preferred absolute viscosity of the mixed suspension containing water base is 20-30 mPa·S.

On this basis, the present invention also provides a method for preparing the nanocomposite porous membrane material, which is based on low viscosity PTFE-NP and SiO ₂ -NP water-based mixed suspension and PI nanofiber nonwoven fabric. Raw materials, through the method of surface coating infiltration or dipping coating infiltration, PTFE-NP and SiO ₂ -NP are filled into the pores of PI nanofiber nonwovens, and after drying at a lower temperature, the temperature is raised to a higher temperature to make Adhesives bond between PTFE-NP and SiO ₂ -NP and between nanospheres and nanoparticles and PI nanofibers.

The preferred preparation method of the nanocomposite porous membrane material of the present invention specifically comprises the following steps:

1) Prepare water-based mixed suspension:

By weight percentage, mix 7-12% of PTFE-NP, 8-13% of SiO ₂ -NP, 0.05-0.15% of dispersant, 1.0-2.5% of binder and the rest of water to obtain a mixed liquid , emulsifying the mixed liquid at a speed of 8000 rpm to form a water-based mixed suspension with an absolute viscosity of 20-30 mPa·S;

2) Preparation of nanocomposite porous membrane material:

The water-based mixed suspension prepared in step 1) is spread on a horizontal plate to form a suspension film of a certain thickness, and then the PI nanofiber nonwoven is covered on the suspension film, and the suspension penetrates into the PI nanofiber In the nonwoven fabric, when the upper layer of the nanofiber cloth is soaked, lift the PI nanofiber nonwoven fabric;

3) Heat the PI nanofiber nonwoven fabric obtained in step 2) at 100-120°C for 8-12 minutes, then raise the temperature to 180-200°C for 3-6 minutes, so that the PTFE-NP and SiO ₂ -NP and They are fully bonded with the PI nanofibers due to the melting of the binder to form the ternary nanocomposite multi-porous membrane of the present invention.

The preferred method for preparing the nanocomposite porous membrane material of the present invention, step 1) the preferred polyacrylate adhesive, more preferably butyl acrylate-isooctyl acrylate copolymer; the dispersant Ammonium polyacrylate is preferred.

In the preferred method of preparing the nanocomposite porous membrane material of the present invention, the PI nanofiber nonwoven fabric described in step 2) preferably has a thickness between 9-38 μm and a porosity preferably between 60-90%. Electrospun PI nanofiber nonwovens.

In the preferred method of preparing the nanocomposite porous membrane material of the present invention, step 3) preferably heat-dries the PI nanofiber nonwoven fabric obtained in step 2) at 100°C for 10 minutes, and then heats up to 200°C for 5 minutes .

The present invention utilizes PTFE-NP to have temperature resistance, lower density, and nano-scale diameter; SiO ₂ -NP has superior temperature resistance, high hardness close to diamond, and diameter smaller than the surface aperture of PI nanofiber nonwovens, etc. , mix and fill them into the pores of PI nanofiber nonwovens, reduce the porosity of PI nanofiber nonwovens and reduce its surface pore size, improve the electrical breakdown strength of the separator, improve the charge retention rate of the battery and eliminate the battery Micro-short circuit phenomenon; at the same time, it improves the thermal shrinkage resistance of the battery separator, and does not greatly increase the areal density of the separator. Therefore, the PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite porous membrane of the present invention is a membrane material very suitable for use as a high-temperature-resistant and high-safety battery diaphragm.

The nanocomposite multi-porous membrane material of the present invention is prepared through specific material selection and process to form an organic/inorganic ternary nanocomposite multi-porous membrane structure with smaller pores than the existing PI nanofiber nonwoven fabric. In its structure, the nanofiber network structure in the PI nanofiber nonwoven fabric plays a supporting role, and PTFE-NP and SiO ₂ -NP play the role of filling and constructing nanopores, thus endowing this organic/inorganic ternary nanocomposite with multiple curvatures. The porous film material has the characteristics of good pore structure, small surface pore size, high breakdown strength, heat resistance and excellent mechanical properties, which overcomes the high porosity, large surface pore size and Low electrical breakdown strength is the Achilles' heel of a safe battery separator; at the same time, the increase in areal density is not too large. When selecting filled composite nanoparticles, the inventors have studied the effect of the ratio between organic nanospheres and inorganic nanoparticles on the material properties, and found that when the composite nanoparticles ratio is higher than 60%, it will lead to the failure of nanoparticle filling. The overall density of the multi-porous membrane is too high, and the pores of the PI nanofiber nonwoven are overfilled, resulting in a composite multi-porous membrane with low porosity and small average pore size; when the proportion of composite nanoparticles is lower than 30%, The insulation of the composite porous membrane is reduced, and the risk of micro-short circuit is relatively large. At the same time, the appropriate ratio between the two types of nanoparticles in the composite particles needs to be controlled, so that the high-quality characteristics of the two types of particles can be balanced. The inventors of the present invention have obtained the optimal ratio range between the two particles through a large number of experiments, so that the overall performance of the composite porous membrane material can be optimized in the optimal ratio range. When selecting a binder and a dispersant, the inventors need to conduct a multi-factor comprehensive screening among various binders and dispersants according to the characteristics of the composite nanoparticle and the needs of the filling process, and finally found that: polyacrylate adhesive The mixture, especially butyl acrylate-isooctyl acrylate copolymer, can provide just the right viscosity for the composite water-based suspension, providing an ideal basis for further coating penetration and particle bonding; the addition of ammonium polyacrylate is relatively Other dispersants are more likely to form an electric double layer on the surface of nanoparticles, which can play a significant role in the dispersion of ultrafine solid particles, can reduce slurry viscosity, prevent particle agglomeration, and make organic and inorganic nanoparticles in water-based suspensions The dispersion has reached a more ideal state. In addition, the preparation method provided by the present invention is more suitable for industrial production than the scraping coating process in the prior art.

Finally, the PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite multi-porous membrane material of the present invention has the following characteristics: the thickness is between 10-40 μm, the porosity is between 30-50%, and the surface pore diameter is between Between 50-800nm, surface density between 18-24g/m ² , tensile strength between 30-50MPa, heat shrinkage temperature greater than 350°C, electrical breakdown strength between 35-50V/μm, ionic conductivity between Between 1.0-8.0×10 ^-3 S·cm ^-1 . The organic/inorganic ternary nanocomposite film with this characteristic is resistant to high temperature, heat shrinkage, high voltage and high current impact, and mechanical impact. And high power lithium battery or super capacitor.

The invention also provides the application of the nanocomposite porous membrane material as a battery diaphragm or a capacitor diaphragm of a non-aqueous electrolyte secondary battery.

detailed description

The following examples will help those of ordinary skill in the art to further understand the present invention, but do not limit the present invention in any form.

Example 1:

An organic/inorganic ternary nanocomposite membrane material, which is based on electrospun polyimide (PI) nanofiber nonwoven fabric, and the pores of the substrate are filled with polytetrafluoroethylene nanospheres (PTFE-NP) and silica nanoparticles (SiO ₂ -NP), the weight ratio of the two is 42/38;

Its preparation method is as follows:

(1) Configuration of polytetrafluoroethylene nanospheres and silica nanoparticles water-based mixed suspension (PTFE-NP/SiO ₂ -NP/H ₂ O-1): polytetrafluoroethylene nanospheres (diameter mainly Distributed at 300nm) 70.0 grams of emulsion (solid content 60wt%), 38.0 grams of silica nanoparticles (main particle size distribution at 200nm), 0.3 grams of ammonium polyacrylate, 8.7 grams of butyl acrylate-isooctyl acrylate copolymer, distilled water 328.0 grams, put into a beaker at one time, emulsify under the rotating speed of 8000 revolutions per minute, form the polytetrafluoroethylene nano-microspheres and silica nano-particle water-based mixed suspension (PTFE-NP /SiO ₂ -NP/H ₂ O-1).

(2) Preparation of PTFE-NP/SiO ₂ -NP/PI ternary nano-composite high-temperature-resistant high-safety battery separator: The PTFE-NP/SiO ₂ -NP/H ₂ O-1 polytetrafluoroethylene nanometer The water-based mixed suspension of microspheres and silica nanoparticles was spread on a glass plate to form a suspension film with a thickness of 40 μm, and then the electrospun PI nanofiber nonwoven fabric with a thickness of 9 μm was covered on PTFE-NP/ _SiO2 -NP/H ₂ O-1 suspension film, the suspension penetrates into the PI nanofiber nonwoven fabric, and when the upper layer of the nanofiber fabric is soaked, it indicates that the pores of the nonwoven fabric are completely filled with the suspension liquid, and the PI nanofiber nonwoven fabric is revealed. Nanofiber non-woven fabrics are heat-baked at 100°C for 10 minutes, then heat-treated at 200°C for 5 minutes, and the polyacrylate copolymer is melted between PTFE-NP nano-microspheres and silica nanoparticles and between them and PI nanofibers. Fully bonded to form an organic/inorganic ternary nanocomposite porous membrane.

(3) Performance characterization: The prepared PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature-resistant high-safety battery separator has a thickness of 11 μm, a tensile strength of 50 MPa, an elongation at break of 40%, and a puncture strength of 4.8N, the heat shrinkage rate at 350°C is 0, the porosity of the multi-porous membrane is 35%, the surface average pore size is 140nm, the gas permeability is 280S under the pressure of 0.48bar, and the electrical breakdown strength is 40V/ μm, the ion conductivity is 5.0×10 ^-3 S·cm ^-1 .

Example 2:

An organic/inorganic ternary nanocomposite membrane material, which is based on electrospun polyimide (PI) nanofiber nonwoven fabric, and the pores of the substrate are filled with polytetrafluoroethylene nanospheres (PTFE-NP) and silica nanoparticles (SiO ₂ -NP), the weight ratio of the two is 30/50;

Its preparation method is as follows:

(1) Configuration of polytetrafluoroethylene nanospheres and silica nanoparticles water-based mixed suspension (PTFE-NP/SiO ₂ -NP/H ₂ O-2): polytetrafluoroethylene nanospheres (diameter mainly Distributed at 300nm) 50.0 grams of emulsion (solid content 60wt%), 50.0 grams of silica nanoparticles (main particle size distribution at 100nm), 0.4 grams of ammonium polyacrylate, 8.6 grams of butyl acrylate-isooctyl acrylate copolymer, distilled water 570.0 grams, put into the beaker at one time, emulsify under the rotating speed of 8000 revolutions per minute, form the polytetrafluoroethylene nano-microsphere and silica nano-particle water-based mixed suspension (PTFE-NP /SiO ₂ -NP/H ₂ O-2).

(2) Preparation of PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high temperature resistant high-safety battery separator: the PTFE-NP/SiO ₂ -NP/H ₂ O-2 polytetrafluoroethylene nano The water-based mixed suspension of microspheres and silica nanoparticles was spread on a glass plate to form a suspension film with a thickness of 60 μm, and then the electrospun PI nanofiber nonwoven fabric with a thickness of 39 μm was covered on PTFE-NP/ _SiO2 -NP/H ₂ O-2 suspension film, the suspension penetrates into the PI nanofiber nonwoven fabric, and when the upper layer of the nanofiber fabric is soaked, it indicates that the pores of the nonwoven fabric are completely filled with the suspension liquid, and the PI nanofiber nonwoven fabric is revealed. For nanofiber nonwovens, heat-bake at 100°C for 10 minutes, then heat-treat at 200°C for 5 minutes, so that the PTFE-NP nanospheres and silica nanoparticles and between them and PI nanofibers are fully bonded by melting polyacrylate. The junction forms an organic/inorganic ternary nanocomposite porous membrane.

(3) Performance characterization: The prepared PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature-resistant high-safety battery separator has a thickness of 40 μm, a tensile strength of 30 MPa, an elongation at break of 45%, and a puncture strength of 40 μm. 7.3N, the heat shrinkage rate at 350°C is 0, the porosity of the multi-porous membrane is 40%, the surface average pore diameter is 90nm, the gas permeability is 150S under the pressure of 0.48bar, and the electric breakdown strength is 37V/ μm, and the ion conductivity is 6.0×10 ^-3 S·cm ^-1 .

Example 3:

An organic/inorganic ternary nanocomposite membrane material, which is based on electrospun polyimide (PI) nanofiber nonwoven fabric, and the pores of the substrate are filled with polytetrafluoroethylene nanospheres (PTFE-NP) and silica nanoparticles (SiO ₂ -NP), the weight ratio of the two is 30/50;

Its preparation method is as follows:

(1) Configuration of polytetrafluoroethylene nanospheres and silica nanoparticles water-based mixed suspension (PTFE-NP/SiO ₂ -NP/H ₂ O-3): polytetrafluoroethylene nanospheres (diameter mainly Distributed at 300nm) 50.0 grams of emulsion (solid content 60wt%), 50.0 grams of silica nanoparticles (main particle size distribution at 500nm), 0.5 grams of ammonium polyacrylate, 8.5 grams of butyl acrylate-isooctyl acrylate copolymer, distilled water 415.0 grams, put into a beaker at one time, emulsify under the rotating speed of 8000 revolutions per minute, form the polytetrafluoroethylene nano-microspheres and silica nano-particle water-based mixed suspension (PTFE-NP /SiO ₂ -NP/H ₂ O-3).

(2) Preparation of PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature-resistant high-safety battery separator: The above-configured PTFE-NP/SiO ₂ -NP/H ₂ O-3 polytetrafluoroethylene nano The water-based mixed suspension of microspheres and silica nanoparticles was spread on a glass plate to form a suspension film with a thickness of 50 μm, and then the electrospun PI nanofiber nonwoven fabric with a thickness of 23 μm was covered on PTFE-NP/ _SiO2 -NP/H ₂ O-2 suspension film, the suspension penetrates into the PI nanofiber nonwoven fabric, and when the upper layer of the nanofiber fabric is soaked, it indicates that the pores of the nonwoven fabric are completely filled with the suspension liquid, and the PI nanofiber nonwoven fabric is revealed. For nanofiber nonwovens, heat-bake at 100°C for 10 minutes, then heat-treat at 200°C for 5 minutes, so that the PTFE-NP nanospheres and silica nanoparticles and between them and PI nanofibers are fully bonded by melting polyacrylate. The junction forms an organic/inorganic ternary nanocomposite porous membrane.

(3) Performance characterization: The prepared PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature resistant high-safety battery separator has a thickness of 25 μm, a tensile strength of 36 MPa, an elongation at break of 38%, and a puncture strength of It is 5.4N, the thermal shrinkage rate at 350°C is 0, the porosity of the multi-porous membrane is 41%, the surface average pore size is 450nm, the gas permeability is 100S under the pressure of 0.48bar, and the electrical breakdown strength is 35V/ μm, and the ion conductivity is 7.0×10 ^-3 S·cm ^-1 .

Example 4:

An organic/inorganic ternary nanocomposite membrane material, which is based on electrospun polyimide (PI) nanofiber nonwoven fabric, and the pores of the substrate are filled with polytetrafluoroethylene nanospheres (PTFE-NP) and silica nanoparticles (SiO ₂ -NP), the weight ratio of the two is 36/44;

Its preparation method is as follows:

(1) Configuration of polytetrafluoroethylene nanospheres and silica nanoparticles water-based mixed suspension (PTFE-NP/SiO ₂ -NP/H ₂ O-4): polytetrafluoroethylene nanospheres (diameter mainly Distributed at 300nm) 60.0 grams of emulsion (solid content 60wt%), 44.0 grams of silica nanoparticles (main particle size distribution at 800nm), 0.4 grams of ammonium polyacrylate, 8.6 grams of butyl acrylate-isooctyl acrylate copolymer, distilled water 273.0 grams, put into a beaker at one time, emulsify under the rotating speed of 8000 revolutions per minute, form the polytetrafluoroethylene nano-microspheres and silica nano-particle water-based mixed suspension (PTFE-NP /SiO ₂ -NP/H ₂ O-4).

(2) Preparation of PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature-resistant high-safety battery separator: The PTFE-NP/SiO ₂ -NP/H ₂ O-4 polytetrafluoroethylene nano The water-based mixed suspension of microspheres and silica nanoparticles was spread flat on a glass plate to form a suspension film with a thickness of 35 μm, and then the electrospun PI nanofiber nonwoven fabric with a thickness of 19 μm was covered on PTFE-NP/ _SiO2 -NP/H ₂ O-4 suspension film, the suspension penetrates into the PI nanofiber nonwoven fabric, and when the upper layer of the nanofiber fabric is soaked, it indicates that the pores of the nonwoven fabric are completely filled with the suspension liquid, and the PI nanofiber nonwoven fabric is revealed. For nanofiber nonwovens, heat-bake at 100°C for 10 minutes, then heat-treat at 200°C for 5 minutes, so that the PTFE-NP nanospheres and silica nanoparticles and between them and PI nanofibers are fully bonded by melting polyacrylate. The junction forms an organic/inorganic ternary nanocomposite porous membrane.

(3) Performance characterization: The prepared PTFE-NP/SiO ₂ -NP/PI ternary nanocomposite high-temperature-resistant high-safety battery separator has a thickness of 20 μm, a tensile strength of 40 MPa, an elongation at break of 38%, and a puncture strength of 6.6N, the heat shrinkage rate at 350°C is 0, the porosity of the multi-porous membrane is 45%, the surface average pore diameter is 800nm, the gas permeability is 30S under the pressure of 0.48bar, and the electric breakdown strength is 40V/ μm, and the ion conductivity is 8.5×10 ^-3 S·cm ^-1 .

The above experimental materials and results test equipment description:

Experimental Materials:

Raw materials such as inorganic nanopowder, PI nanofiber nonwoven fabric, polymer dispersant and polymer binder used in the 4 experimental examples of the present invention were purchased through commercial channels.

Polytetrafluoroethylene nano-microsphere emulsion and silica nano-powder are purchased through the Alibaba sales platform, Shandong Jingxin Crystal Technology Co., Ltd. and Beijing Deke Daojin Technology Co., Ltd.;

Electrospun polyimide nanofiber nonwoven fabric, produced by Jiangxi Xiancai Nanofiber Technology Co., Ltd.;

Ammonium polyacrylate was purchased from Shandong Zibo Jinghe Dye Chemical Co., Ltd.;

(2) Test and characterization of experimental results

The experimental results of the 4 experimental examples in the present invention are routinely tested and characterized by the following instruments and equipment.

Polymer solution and spinning solution absolute viscosity are measured with NDJ-8S viscometer (Shanghai Precision Scientific Instrument Company);

The diameter of the electrospun nanofibers was determined with a scanning electron microscope VEGA 3 SBU (Czech Republic);

The thermal decomposition temperature of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nanocomposite high-temperature-resistant high-safety battery separator was measured by WRT-3P thermogravimetric analyzer (TGA) (Shanghai Precision Scientific Instrument Co., Ltd.);

The mechanical properties (strength, elongation at break, etc.) of PTFE-NP SiO ₂ -NP/PI organic/inorganic ternary nanocomposite high-temperature-resistant high-safety battery separators were measured with CMT8102 micro-controlled electronic universal testing machine (Shenzhen SANS Material Testing Co., Ltd.) ;

The glass transition temperature of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nanocomposite high-temperature-resistant high-safety battery separator is determined by using Diamond Dynamic Mechanical Analyzer (DMA) (Perkin-Elmer, USA);

The porosity of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nanocomposite high-temperature-resistant high-safety battery separator is calculated by the following formula:

Porosity β=[1-(ρ/ρ _o )]×100

Where ρ is the density (g/cm3) of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nanocomposite multi-porous membrane, ρ _o is PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary Density (g/cm ³ ) of nanocomposite solid films (prepared by solution casting);

The air permeability and surface pore size of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nano-composite high-temperature-resistant high-safety battery separator are measured by Porometer 3G air permeability tester from the United States;

The ionic conductivity of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nanocomposite high-temperature resistant high-safety battery separator was measured using an electrochemical workstation CHI 660D (Chenhua Instruments, Shanghai, China);

The electrical breakdown strength of PTFE-NP/SiO ₂ -NP/PI organic/inorganic ternary nano-composite high-temperature-resistant high-safety battery separator is measured with a ZHZ 8 withstand voltage tester from Shanghai Hengmei Electric Co., Ltd.

Claims (5)

1. a kind of nano combined many curved hole membrane materials, it is a kind of organic/inorganic ternary nano composite film material, and it is poly- with electrospinning Polyimide PI nano-fiber for production of non-woven is base material, and polytetrafluorethylenano nano-microsphere PTFE-NP and two is filled with substrate pores Silica nano particle SiO₂- NP, both weight ratios are 42/38；

Its preparation method is as follows：

(1) polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE-NP/SiO of nano SiO 2 particle₂-NP/H₂O-1 Configuration：Take diameter and be mainly distributed on 300nm and polytetrafluorethylenano nano-microsphere emulsion 70.0 gram, master of the solid content for 60wt% Want particle diameter distribution different in 38.0 grams of the nano SiO 2 particle of 200nm, 0.3 gram of ammonium polyacrylate, butylacrylate-acrylic acid 8.7 grams of monooctyl ester copolymer, 328.0 grams of distilled water, are disposably put into beaker, shape emulsified in 8000 turns per minute of rotating speed It is the polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE- of nano SiO 2 particle of 29mPaS into absolute viscosity NP/SiO₂-NP/H₂O-1；

(2)PTFE-NP/SiO₂The preparation of-NP/PI ternary nano complex fire resistant high safety battery diaphragms：By what is configured above PTFE-NP/SiO₂-NP/H₂O-1 polytetrafluorethylenano nano-microspheres and the water base mixing suspension of nano SiO 2 particle are in glass Then plate upper berth flat shape covers the electrospinning PI nano-fiber for production of non-woven that thickness is 9 μm into the suspension liquid and membrane that thickness is 40 μm In PTFE-NP/SiO₂-NP/H₂In O-1 suspension liquid and membranes, suspension is infiltered in PI nano-fiber for production of non-woven, treats nano-fiber cloth Upper strata is drenched, and suspension has been fully filled with the hole for showing non-weaving cloth, PI nano-fiber for production of non-woven is uncovered, 100 Heat dries 10min at DEG C, is warming up to 200 DEG C of heat treatment 5min, make between PTFE-NP Nano microspheres and nano SiO 2 particle and They are melted and between PI nanofibers by acrylate copolymer and the organic/inorganic ternary of well-bonded formation is nano combined Many curved hole films.

2. a kind of nano combined many curved hole membrane materials, it is a kind of organic/inorganic ternary nano composite film material, and it is poly- with electrospinning Polyimide PI nano-fiber for production of non-woven is base material, and polytetrafluorethylenano nano-microsphere PTFE-NP and two is filled with substrate pores Silica nano particle SiO₂- NP, both weight ratios are 30/50；

Its preparation method is as follows：

(1) polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE-NP/SiO of nano SiO 2 particle₂-NP/H₂O-2 Configuration：Take diameter and be mainly distributed on 300nm and polytetrafluorethylenano nano-microsphere emulsion 50.0 gram, master of the solid content for 60wt% Want particle diameter distribution different in 50.0 grams of the nano SiO 2 particle of 100nm, 0.4 gram of ammonium polyacrylate, butylacrylate-acrylic acid 8.6 grams of monooctyl ester copolymer, 570.0 grams of distilled water, are disposably put into beaker, shape emulsified in 8000 turns per minute of rotating speed It is the polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE- of nano SiO 2 particle of 21mPaS into absolute viscosity NP/SiO₂-NP/H₂O-2；

(2)PTFE-NP/SiO₂The preparation of-NP/PI ternary nano complex fire resistant high safety battery diaphragms：By what is configured above PTFE-NP/SiO₂-NP/H₂O-2 polytetrafluorethylenano nano-microspheres and the water base mixing suspension of nano SiO 2 particle are in glass Then plate upper berth flat shape covers the electrospinning PI nano-fiber for production of non-woven that thickness is 39 μm into the suspension liquid and membrane that thickness is 60 μm In PTFE-NP/SiO₂-NP/H₂In O-2 suspension liquid and membranes, suspension is infiltered in PI nano-fiber for production of non-woven, treats nano-fiber cloth Upper strata is drenched, and suspension has been fully filled with the hole for showing non-weaving cloth, PI nano-fiber for production of non-woven is uncovered, 100 Heat dries 10min at DEG C, is warming up to 200 DEG C of heat treatment 5min, make between PTFE-NP Nano microspheres and nano SiO 2 particle and They are melted and the well-bonded formation nano combined many curved hole of organic/inorganic ternary and between PI nanofibers by polyacrylate Film.

3. a kind of nano combined many curved hole membrane materials, it is a kind of organic/inorganic ternary nano composite film material, and it is poly- with electrospinning Polyimide PI nano-fiber for production of non-woven is base material, and polytetrafluorethylenano nano-microsphere PTFE-NP and two is filled with substrate pores Silica nano particle SiO₂- NP, both weight ratios are 30/50；

Its preparation method is as follows：

(1) polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE-NP/SiO of nano SiO 2 particle₂-NP/H₂O-3 Configuration：Take diameter and be mainly distributed on 300nm and polytetrafluorethylenano nano-microsphere emulsion 50.0 gram, master of the solid content for 60wt% Want particle diameter distribution different in 50.0 grams of the nano SiO 2 particle of 500nm, 0.5 gram of ammonium polyacrylate, butylacrylate-acrylic acid 8.5 grams of monooctyl ester copolymer, 415.0 grams of distilled water, are disposably put into beaker, shape emulsified in 8000 turns per minute of rotating speed It is the polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE- of nano SiO 2 particle of 24mPaS into absolute viscosity NP/SiO₂-NP/H₂O-3；

(2)PTFE-NP/SiO₂The preparation of-NP/PI ternary nano complex fire resistant high safety battery diaphragms：By what is configured above PTFE-NP/SiO₂-NP/H₂O-3 polytetrafluorethylenano nano-microspheres and the water base mixing suspension of nano SiO 2 particle are in glass Then plate upper berth flat shape covers the electrospinning PI nano-fiber for production of non-woven that thickness is 23 μm into the suspension liquid and membrane that thickness is 50 μm In PTFE-NP/SiO₂-NP/H₂In O-2 suspension liquid and membranes, suspension is infiltered in PI nano-fiber for production of non-woven, treats nano-fiber cloth Upper strata is drenched, and suspension has been fully filled with the hole for showing non-weaving cloth, PI nano-fiber for production of non-woven is uncovered, 100 Heat dries 10min at DEG C, is warming up to 200 DEG C of heat treatment 5min, make between PTFE-NP Nano microspheres and nano SiO 2 particle and They are melted and the well-bonded formation nano combined many curved hole of organic/inorganic ternary and between PI nanofibers by polyacrylate Film.

4. a kind of nano combined many curved hole membrane materials, it is a kind of organic/inorganic ternary nano composite film material, and it is poly- with electrospinning Polyimide PI nano-fiber for production of non-woven is base material, and polytetrafluorethylenano nano-microsphere PTFE-NP and two is filled with substrate pores Silica nano particle SiO₂- NP, both weight ratios are 36/44；

Its preparation method is as follows：

(1) polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE-NP/SiO of nano SiO 2 particle₂-NP/H₂O-4 Configuration：Take diameter and be mainly distributed on 300nm and polytetrafluorethylenano nano-microsphere emulsion 60.0 gram, master of the solid content for 60wt% Want particle diameter distribution different in 44.0 grams of the nano SiO 2 particle of 800nm, 0.4 gram of ammonium polyacrylate, butylacrylate-acrylic acid 8.6 grams of monooctyl ester copolymer, 273.0 grams of distilled water, are disposably put into beaker, shape emulsified in 8000 turns per minute of rotating speed It is the polytetrafluorethylenano nano-microsphere and the water base mixing suspension PTFE- of nano SiO 2 particle of 27mPaS into absolute viscosity NP/SiO₂-NP/H₂O-4；

(2)PTFE-NP/SiO₂The preparation of-NP/PI ternary nano complex fire resistant high safety battery diaphragms：By what is configured above PTFE-NP/SiO₂-NP/H₂O-4 polytetrafluorethylenano nano-microspheres and the water base mixing suspension of nano SiO 2 particle are in glass Then plate upper berth flat shape covers the electrospinning PI nano-fiber for production of non-woven that thickness is 19 μm into the suspension liquid and membrane that thickness is 35 μm In PTFE-NP/SiO₂-NP/H₂In O-4 suspension liquid and membranes, suspension is infiltered in PI nano-fiber for production of non-woven, treats nano-fiber cloth Upper strata is drenched, and suspension has been fully filled with the hole for showing non-weaving cloth, PI nano-fiber for production of non-woven is uncovered, 100 Heat dries 10min at DEG C, is warming up to 200 DEG C of heat treatment 5min, make between PTFE-NP Nano microspheres and nano SiO 2 particle and They are melted and the well-bonded formation nano combined many curved hole of organic/inorganic ternary and between PI nanofibers by polyacrylate Film.

5. the nano combined many curved hole membrane materials described in claim 1-4 as rechargeable nonaqueous electrolytic battery battery diaphragm or The application of capacitor diaphragm.