WO2013181967A1

WO2013181967A1 - Ion polymer membrane material, preparation process therefor and lithium secondary battery

Info

Publication number: WO2013181967A1
Application number: PCT/CN2013/073856
Authority: WO
Inventors: 潘中来; 黄兴兰; 马先果; 邓佳闽; 王璐; 高建东; 杜鸿昌; 李仁贵; 邓正华
Original assignee: 成都中科来方能源科技有限公司
Priority date: 2012-06-04
Filing date: 2013-04-08
Publication date: 2013-12-12
Also published as: TW201351759A; TWI511352B

Abstract

An ion polymer membrane material and an ion polymer membrane material/ceramic composite membrane material relate to the field of the manufacture of lithium batteries. The ion polymer membrane material is composed of polymer colloid particles with sulfonate groups on the surface thereof. The ion polymer membrane material is obtained using a reactive sulfonate surfactant as an emulsifying agent to synthesize an emulsion of acrylic polymer colloid with sulfonate groups on the surface thereof, and subjecting the emulsion to a casting and film-forming process to form a membrane. The ion polymer/ceramic filler composite membrane material is composed of the polymer colloidal particles with sulfonate groups on the surface thereof and a ceramic filler. The ion polymer/ceramic filler composite membrane material is obtained using a reactive sulfonate surfactant as an emulsifying agent to synthesize an emulsion of acrylic polymer colloid with sulfonate groups on the surface thereof, adding a ceramic filler slurry to the emulsion of acrylic polymer colloid, and after full dispersion to uniformity, subjecting the emulsion to a casting and film-forming process to form an ion polymer/ceramic filler composite membrane keeping the colloid particle structure.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator material for an energy storage device such as a lithium ion secondary battery and a method of producing the same, and relates to the field of lithium battery manufacturing. Background Art A battery is composed of a positive electrode, a negative electrode, a separator, and an electrolyte. The separator is one of the important components in the battery. Its function in the battery is to act as a separator between the positive and negative electrodes inside the battery. It prevents the direct contact between the positive and negative electrodes and causes internal short circuit. At the same time, it is necessary to isolate the electrons and ensure the electrolyte. The ions pass smoothly to support the electrochemical reaction of the battery. Its microporous structure, physical properties, chemical properties, thermal properties, etc. are closely related to battery performance. For the separator of a lithium ion battery, since the lithium ion battery has a high operating voltage, the oxidation property of the positive electrode material and the reduction property of the negative electrode material are high, the lithium ion battery separator material and the highly electrochemically active positive and negative electrode materials should have an excellent phase. Capacitance, should also have excellent stability, solvent resistance, ionic conductivity, electronic insulation, good mechanical strength, high heat resistance and fuse isolation. The physical and chemical properties of the membrane depend on the material of the membrane material. Different membranes have different physical and chemical properties and thus exhibit significantly different battery performance in the battery.

Commercialized lithium ion batteries, metal lithium secondary batteries, and battery separators used in lithium-sulfur batteries, mainly polyolefin microporous membranes. The role of the microporous membrane in the battery is to act as a separator between the positive and negative electrodes inside the battery, to prevent internal short circuit caused by direct contact between the positive and negative electrodes, and to isolate electrons while ensuring smooth passage of ions in the electrolyte to support the battery. Electrochemical reaction.

Commercialized lithium ion batteries, metal lithium secondary batteries, and battery separators used in lithium-sulfur batteries, mainly polyolefin microporous membranes. There are two technical routes for the production of polyolefin microporous membranes: one is the dry technical route; the other is the wet technical route.

In the dry method, a polyolefin resin is melted, extruded, and blown into a film to form a crystalline polymer film, which is subjected to crystallization treatment and annealing to obtain a highly oriented multilayer structure, which is further stretched at a high temperature to form a crystal interface. Peeling is performed to form a porous structure, and the pore diameter of the film can be increased. The dry method can be divided into dry uniaxial stretching and biaxial stretching according to different stretching directions.

The dry uniaxial stretching process is a method of producing a highly crystalline oriented film by using a method of hard elastic fibers to prepare a highly oriented PE or PP separator having a low crystallinity and then annealing at a high temperature. The film is first stretched at a low temperature to form defects such as silver streaks, and then the defects are pulled apart at a high temperature to form micropores. At present, the United States Celgard company, Japan Ube company use this The process produces a single layer of PE, PP and a 3-layer PP / PE / PP composite film. The membrane produced by this process has a flat long microporous structure, and since the uniaxial stretching is performed only, the transverse strength of the separator is relatively poor, but there is almost no heat shrinkage in the transverse direction.

The dry biaxial stretching process is a preparation process developed by the Institute of Chemistry of the Chinese Academy of Sciences in the early 1990s. By adding a nucleation β crystal modifier in PP, the crystal form is transformed into micropores during the stretching process by utilizing the difference in density between different phases of ruthenium. Compared with uniaxial stretching, the strength in the transverse direction is improved, and the transverse and longitudinal stretching ratios can be appropriately changed according to the strength requirements of the separator to obtain desired properties.

The dry stretching process is simple and non-polluting, and is a common method for preparing lithium ion battery separators. However, the pore size and porosity of the process are difficult to control, and the stretching is relatively small, only about 1 to 3, while stretching at low temperature. It is easy to cause perforation of the diaphragm, and the product cannot be made very thin.

The wet method is also called phase separation method or thermal phase separation method. The liquid hydrocarbon or some small molecular substances are mixed with the polyolefin resin, heated and melted to form a uniform mixture, and then the temperature is separated for phase separation, and the membrane is pressed to be pressed. The membrane is heated to near the melting point temperature, biaxially stretched to orient the molecular chain, and finally kept for a certain period of time, and the residual solvent is eluted with a volatile substance to prepare a microporous membrane material which is interpenetrated. The method is applicable to a wide range of materials. . The pore size range of the membrane produced by the wet biaxial stretching method is on the order of the size of the phase micro interface, which is relatively small and uniform, and the biaxial stretching ratio can reach 5 to 7, so that the membrane performance is isotropic and the transverse tensile strength is high. The puncture strength is large, the normal process will not cause perforation, the product can be made thinner, and the battery energy density is higher.

It can be seen from the manufacturing process of polyolefin microporous membrane that whether it is dry or wet, mechanical stretching is carried out before the hole is formed, and the polyolefin resin used is polypropylene (ΡΡ) or polyethylene (ΡΕ) non-polar. Sexual material. Due to the inherent chemical and physical properties of the tantalum or niobium material and the microporous membrane manufacturing process, there are performance defects in the polyolefin microporous membrane to ensure the safety and service life of the lithium ion battery.

The main problems of polyolefin microporous membrane: First, the microporous membrane has poor liquid absorption and liquid retention ability. Tantalum or niobium is a non-polar material, which has poor affinity with strong polar electrolyte solution, electrolyte and The lower affinity of the polyolefin microporous membrane leads to the poor absorption and retention of the microporous membrane. The absorption and retention of the microporous membrane is closely related to the charge and discharge cycle life of the battery. Second, the microporous membrane is poor in thermal stability, because the polyolefin microporous membrane is a microporous membrane obtained by mechanical stretching, or mechanically stretching and then extracting the pores with an organic solvent, and being heat-set. The preparation process causes residual stress in the microporous membrane, so that the microporous membrane has a shape memory effect. When the temperature of the polyolefin resin is close to the softening point, the microporous membrane tends to restore the shape before stretching and produces a larger shape. Shrinkage, microporous film heat shrinkage must accompany volume shrinkage, film area shrinkage occurs, so that the microporous membrane loses the barrier between positive and negative, thus causing a short circuit between the positive and negative electrodes inside the battery, causing battery burning, Security issues such as explosions.

Based on the performance defects of polyolefin microporous membranes and the causes of these performance defects, the inventors of the present invention have A lithium ion battery separator having a thermal expansion fusion closing effect (Chinese Patent Application No. CN 102280605A) has been proposed, which comprises a microporous polyolefin membrane and a surface coated with a polymer colloidal particle coating having a particle size of 10 to 100 nm. . The polymer colloidal particle coating is a polymer colloidal emulsion formed by polymerizing acrylonitrile in an organic solvent of EVA, and is formed by drying on the surface of the microporous polyolefin separator. The modified membrane has a thermal expansion and fusion closing effect, good thermal stability, low shrinkage after heating, and avoids burning and explosion of the battery. It improves the safety and reliability of the battery; in addition, it has good liquid absorption and liquid retention ability for the electrolyte melt, thereby giving the lithium ion battery excellent cycle life.

The inventors of the present invention believe that although the film has good battery performance and safety, it is obtained by modifying on the basis of the microporous polyolefin separator, which is bound to increase the cost of the battery separator and is practically affected by the separator. In addition, the film needs to use a large amount of toluene as a solvent in the preparation process, which has a problem of environmental pollution and also increases the manufacturing cost of the polymer film.

Disclosure of the Invention An object of the present invention is to provide a non-porous dense film having an colloidal particle structure, an ionic polymer film material. The ionic polymer film material provided by the present invention is composed of polymer colloidal particles having a sulfonate group on the surface. It is a non-porous dense membrane that does not cause significant heat shrinkage when the battery is overheated.

Preferably, the polymer colloidal particles having a sulfonate group on the surface are acrylate-based polymer colloidal particles having a sulfonate group on the surface, which ensures that the ionic polymer membrane material and the electrolyte have Better compatibility.

The ionic polymer membrane material of the present invention is a polymer colloidal emulsion having a sulfonate group on its surface during the polymerization reaction using a reactive sulfonate surfactant as an emulsifier. The reactive sulfonate surfactants are vinyl sulfonate, allyl sulfonate, methallyl sulfonate, allyloxy hydroxypropyl sulfonate, hydroxypropyl methacrylate One or more of a sulfonate, 2-acrylamido-2-methylpropanesulfonate, and a styrenesulfonate are used in combination; wherein the cation is a lithium ion, a sodium ion or a potassium ion.

The polymer colloidal emulsion is cast into a film to form a polymer film that maintains a colloidal particle structure. When the battery is overheated, the diaphragm does not substantially shrink. In addition, since the polymer film absorbs the electrolyte, a colloidal ion conduction path is formed between the colloidal particles and the colloidal particles, and after absorbing the electrolyte solution or the solvent, the ionic polymer film material can still maintain the colloidal particle structure, and the colloidal particle spherical structure The dense accumulation increases the tortuosity of the ion conduction path and improves the electronic insulation performance of the polyanion electrolyte membrane.

After forming a polymer colloidal emulsion with a sulfonate group on the surface, the colloidal particles were observed by scanning electron microscopy. The average particle size ranges from 10 nm to 1.0 m, preferably from 20 to 200 nm. The ionic polymer film has a thickness of 10 to 40 m. A second object of the present invention is to form an ionic polymer/ceramic composite film by adding a ceramic filler to the above ionic polymer film to increase the rigidity of the ionic polymer film and to reduce the deformation of the ionic polymer film. It is still a dense film with no 90 pores.

The ionic polymer membrane material of the present invention is a polymer colloidal emulsion having a sulfonate group on its surface during the polymerization reaction using a reactive sulfonate surfactant as an emulsifier. A ceramic filler 95 slurry is added to the above polymer colloidal emulsion, uniformly dispersed, and then cast into a film to form an ionic polymer/ceramic filler composite film. The ionic polymer/ceramic filler composite film forms a penetrating ion conduction path between the colloidal particles and the colloidal particles after absorbing the electrolyte, and the composite film material can maintain the colloidal particle structure after absorbing the electrolyte solution or solvent. The dense packing of the colloidal particle structure and the ceramic filler particles uniformly dispersed in the film increase the tortuosity of the ion conduction path and improve the electronic insulation properties of the polyelectrolytic film. At the same time, the presence of ceramic filler particles increases the rigidity of the ionic polymer film and reduces the deformation of the ion 100 polymer film.

The reactive sulfonate surfactants are vinyl sulfonate, allyl sulfonate, methallyl sulfonate, allyloxy hydroxypropyl sulfonate, hydroxypropyl methacrylate One or more of a sulfonate, 2-acrylamido-2-methylpropanesulfonate, and a styrenesulfonate are used in combination; wherein the cation is a lithium ion, a sodium ion or a potassium ion.

The preferred particle size range of the ceramic filler particles is from 10 nm to 5.00; the preferred particle size of the ceramic filler particles is from 10 nm to 5.00; Yes, the average particle size of the colloidal particles ranges from 20 to 200 nm, and the average particle size of the ceramic filler particles ranges from 20 nn! 〜 0. 5 ; more preferably 20 nm to 200 nm.

The ceramic filler particles account for 10-60% by mass of the film. It is preferably 15-50%, more preferably 25-30%. The ionic polymer/ceramic filler composite film has a thickness of 10 to 40 m. The following are the preparation methods:

110 The ionic polymer film of the present invention is prepared by the following method:

a. Synthesis of polymer colloidal emulsion: Add colloidal protective agent and distilled water to the reaction flask, heat and stir until completely dissolved, and add reactive sulfonate surfactant, polymerization monomer and crosslinker (in any order) Uniform, then adding initiator polymerization to obtain a polymer colloidal emulsion; b. Polymer colloidal emulsion, coated on a plastic base tape, peeled off after drying.

115. As a preferred embodiment of the present invention, the polymerization monomer is methyl acrylate.

The reactive sulfonate surfactants of the above methods are vinyl sulfonate, allyl sulfonate, methallyl sulfonate, allyloxy hydroxypropyl sulfonate, hydroxy methacrylate One or more of propyl sulfonate, 2-acrylamido-2-methylpropane sulfonate, and styrene sulfonate are used in combination; wherein the cation is a lithium ion, a sodium ion or a potassium ion.

In order to adjust the heat shrinkability of the film material, the liquid absorbing ability of the electrolyte, and the flexibility of the polymer, etc., a further preferred embodiment of the present invention is to add a second polymerization monomer CH to the polymerization reaction system. ^CRiR ^{2 is} subjected to polymerization.

Wherein R - H or a CH ₃ ; R ² = - C ₆ H ₅ , an OCOCH ₃ , a CN, a C ₄ H ₆ ON, a C ₂ H ₃ C0 ₃ , -COO ( CH ₂ ) _n CH ₃ , n is 0~14.

The second monomer is used in combination of any one or more of the above monomers in an amount of 2 to 125 50%, preferably 2 to 10% by weight based on the total mass of the polymerizable monomers.

As a preferred embodiment of the present invention, the starting materials for the polymerization: the reactive sulfonate surfactant, the polymerization monomer and the crosslinking agent are added in one portion, dropwise or stepwise. The polymerization monomer described herein is a combination of a methyl acrylate monomer or a methyl acrylate monomer and a second monomer.

Further preferably, 1/5 to 1/3 of the raw material (by weight) of the polymerization reaction is first added, and the polymerization reaction is carried out for 130 minutes, and then the raw materials of the remaining polymerization are added dropwise or stepwise.

The polymerization reaction time is preferably completed to complete the polymerization reaction. Usually 4-36 hours, preferably 8 to 24 hours.

The polymerization temperature is 50 to 90 ° C, preferably 55 to 70 ° C.

The ionic polymer/ceramic filler composite film of the present invention is prepared by the following method:

135 1. Synthesis of polymer colloidal emulsion: Add colloidal protective agent and distilled water to the reaction flask, heat and stir until completely dissolved, add reactive sulfonate surfactant, polymerization monomer and crosslinker (in any order) Mixing uniformly, then adding initiator polymerization to obtain a polymer colloidal emulsion;

2. Preparation of ceramic filler slurry: Ceramic filler and dispersant are added to distilled water. After dispersing evenly, it is further milled and dispersed by a ball mill. The sieve is passed through 200 mesh to remove the unmilled larger particles.

140 3. Add the polymer colloidal emulsion prepared in step 1 to the ceramic filler slurry prepared in step 2, disperse uniformly and then apply it on a plastic base tape, such as PET (polyethylene terephthalate) base tape, and bake. After drying the water, it is peeled off to obtain an ionic polymer/ceramic filler composite film. The mass percentage of the ceramic filler in the ionic polymer/ceramic filler composite film is 10-60%. It is preferably 15-50%.

145

As a preferred embodiment of the present invention, the reactive sulfonate surfactant of the above method is vinyl sulfonate, allyl sulfonate, methallyl sulfonate, allyloxy hydroxypropyl sulfonate. a mixture of one or more of an acid salt, a hydroxypropyl methacrylate sulfonate, a 2-acrylamido-2-methylpropane sulfonate, and a styrene sulfonate; wherein the cation is a lithium ion, The sodium ion or potassium ion is used in an amount of 2 to 50%, preferably 2 to 10%, based on the total mass of the polymerization monomer.

150. In a preferred embodiment of the present invention, the colloidal protective agent described in the step 1 is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone, and preferably polyvinyl alcohol. The amount of the colloidal protective agent is 5 to 30%, preferably 10 to 25%, based on the total mass of the polymerization monomer.

The dispersing agent in the step 2 is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone, preferably polyvinyl alcohol. In the ceramic filler slurry, the content of the ceramic filler is 80 to 95%, the content of the dispersant is 5 to 155 20%, and the solid content of the slurry is 20 to 50%.

As a preferred embodiment of the present invention, the polymerizable monomer is methyl acrylate, and the methyl acrylate content in the polymer colloid is 40 to 80%.

In order to adjust the heat shrinkability of the film material, the liquid absorbing ability of the electrolyte, and the flexibility of the polymer, etc., a further preferred embodiment of the present invention is to add a second polymerizable monomer CH _{2 to the} polymerization reaction system. =CR R _{2 to} carry out polymerization 160 reaction;

Wherein -H or a CH ₃ ; R ₂ = _C ₆ H ₅ , _OCOCH ₃ , a CN, a C ₄ H ₆ ON, _C ₂ H ₃ C0 ₃ , — COO(CH ₂ )nCH ₃ , n is 0~ 14.

The second monomer is used in combination of any one or more of the above monomers in an amount of 2 to 50%, preferably 2 to 10% based on the total mass of the polymerizable monomers.

The crosslinking agent described in 165 is a polymerizable monomer having two or more double bonds, such as divinylbenzene, trimethylolpropane triacrylate, dipropylene adipate, methylene. 0〜10. 0%。 The bis acrylamide, the amount of the total weight of the polymerization monomer is 2. 0~10. 0%.

0%。 The initiator is 0. 2~1. 0%。 The initiator is 0. 2~1. 0%.

170 As a preferred embodiment of the present invention, the starting materials for the polymerization: the reactive sulfonate surfactant, the polymerization monomer and the crosslinking agent are added in one portion, dropwise or stepwise. The polymerization monomer described herein is methyl acrylate A combination of a monomer or a methyl acrylate monomer and a second monomer.

Further preferably, 1/5 to 1/3 of the raw material (by weight) of the polymerization reaction is first added, and after the polymerization reaction for a certain period of time, the remaining polymerization raw materials are added dropwise or stepwise.

175 The polymerization reaction time is preferably 92% or more of the conversion ratio of the monomer polymerization reaction. Usually 4-36 hours, preferably 8~24 hours.

The polymerization temperature is 50 to 90 ° C, preferably 55 to 70 ° C.

The ceramic filler is a metal oxide and a metal composite oxide, and has the general formula NzMxOy, wherein N is an alkali metal or alkaline earth metal element, M is a metal element, Z is 0 to 5, and X is 1 to 6, y is 1 to 15. The average grain diameter (D50) of the ceramic filler is 10 nn! ~ 5.0, preferably 20 nn! 〜 0.5 , the preferred ceramic filler is A1 ₂ 0 ₃ and the average particle diameter (D50) is 20 nm to 200 nm. Advantageous Effects of the Invention The present invention provides a lithium ion battery separator and an ionic polymer/ceramic filler composite membrane which are simple in production process, low in manufacturing cost, environmentally friendly, non-polluting, and environmentally friendly with water as a dispersion medium. .

185 The ionic polymer membrane material of the invention is composed of acrylate polymer colloidal particles, and the ionic polymer/ceramic filler composite membrane material is composed of acrylate polymer colloid particles and inorganic filler, and the solubility parameter of the acrylate polymer is The solubility parameters of the electrolyte organic solvent are similar, which ensures that the ionic polymer/ceramic filler composite membrane has good compatibility with the electrolyte, achieves good liquid absorption and liquid retention capacity, and can improve battery cycle life.

The invention is made by using a polymer colloidal emulsion casting film forming process, and the obtained product is a non-porous dense film, which should not be

190 force residual, when the battery is overheated, the diaphragm has no obvious heat shrinkage, thus preventing the internal and negative internal short circuit of the battery. The ionic polymer/ceramic filler composite film absorbs the electrolyte and forms a penetrating ion conduction path between the colloidal particles and the colloidal particles, and after absorbing the electrolyte solution or solvent, the composite film material can maintain the colloidal particle structure. The dense packing of the colloidal particle structure and the ceramic filler particles uniformly dispersed in the film increase the tortuosity of the ion conduction path and improve the electronic insulation performance of the polyelectrolyte film. At the same time, the presence of ceramic filler particles increases the rigidity of the ionic polymer film and reduces

Deformation of 195 ionic polymer film.

DRAWINGS

Figure 1. Schematic diagram of polymer colloidal particles containing a sulfonate group on a single surface, a for the sulfonate group and b for the polymer colloidal particles bearing the sulfonate group on the surface.

Figure 2 is a schematic illustration of a polymer colloidal emulsion containing a sulfonate group on the surface.

200 Figure 3 is a schematic representation of an ionic polymer film composed of polymer colloidal particles containing sulfonate groups on the surface. 4 is an SEM after immersion of the ionic polymer membrane electrolyte of the present invention.

Fig. 5 is a graph showing the charge and discharge characteristics of a lithium battery in which the ionic polymer film of the present invention is a separator, and the ordinate is the voltage (V) and the abscissa is the gram capacity (mAh/g).

Fig. 6 is a graph showing the capacity retention ratio of the ionic polymer film during the charge and discharge cycle of the lithium battery as a function of the number of cycles. The vertical 205 coordinate is the capacity retention ratio (%), and the abscissa is the number of cycles (times).

7 is a comparison of discharge curves of lithium batteries prepared by the ionic polymer film and the ionic polymer/A1 ₂ ₃ composite film prepared in Example 1 and Example 13, wherein the ordinate is voltage (V) and the abscissa is gram capacity (mAh/). g), a is an ionic polymer/A1 ₂ 0 ₃ composite membrane battery, and b is an ionic polymer membrane battery.

Figure 8 is a diagram showing the fifth and 100th charge and discharge curves of a lithium battery of the ionic polymer/A1 ₂ ₃ composite film prepared in Example 13, with the ordinate on the voltage (V) and the abscissa as the gram capacity (mAh/). g), A is the 5th charge and discharge curve, and B is the 100th charge and discharge curve.

Figure 9 is a scanning electron micrograph of the ionic polymer/A1 ₂ ₃ composite film prepared in Example 13. The invention is further described in detail below by way of specific examples, but does not represent that the invention can be practiced in the following manner.

215 Detailed Description

The ionic polymer film material is composed of acrylate-based polymer colloidal particles having a sulfonate group on the surface. The polymer is preferably an acrylate-based polymer having a solvent solubility parameter similar to that used in the electrolyte, and the strong polar group on the surface of the ionic polymer film forms a chemical association with the super solvent of the non-aqueous electrolyte, thereby ensuring the present invention. The ionic polymer membrane material has good compatibility with the electrolyte, and achieves good liquid absorption and liquid retention capabilities.

The ionic polymer film material of the present invention is an acrylate polymer colloidal emulsion having a sulfonate group on the surface thereof during the polymerization reaction using a reactive sulfonate surfactant as an emulsifier. The emulsion is cast into a film to form a polymer film that maintains the structure of the colloidal particles. When the polymer film having the colloidal particle structure absorbs the electrolyte solution, a through ion conduction path can be formed between the colloidal particles, and after the electrolyte solution or the solvent is absorbed, the ionic polymer film material can maintain the colloidal particle structure, colloid. Dense packing of particle sphere structure, increasing ion conduction path

The tortuosity of 225 improves the electrical insulation properties of the polyanion electrolyte membrane.

As a preferred embodiment of the present invention, after forming a film of a polymer colloidal emulsion having a sulfonate group on the surface, the average particle diameter of the colloidal particles is observed by a scanning electron microscope to be in the range of 10 nm to 1.0 m, preferably 20 to 200 nm. The ionic polymer film has a thickness of 10 to 40 m. The reactive sulfonate surfactants are vinyl sulfonate, allyl sulfonate, methallyl sulfonate, 230 allyloxy hydroxypropyl sulfonate, hydroxypropyl methacrylate One or more of a sulfonate, a 2-acrylamido-2-methylpropanesulfonate, and a styrenesulfonate are used in combination; wherein the cation is a lithium ion, a sodium ion or a potassium ion.

The ionic polymer film is prepared by the following method:

a. Synthesis of polymer colloidal emulsion: Add colloidal protective agent and distilled water to the reaction flask, heat and stir until completely dissolved, and add reactive sulfonate surfactant, polymerization monomer and crosslinker (in any order) Evenly,

235 then adding an initiator polymerization to obtain a polymer colloidal emulsion;

b. Polymer colloidal emulsion, coated on a plastic base tape, peeled off after drying.

As a preferred embodiment of the present invention, the polymerizable monomer is methyl acrylate.

In order to adjust the heat shrinkability of the film material, the liquid absorbing ability of the electrolyte, and the flexibility of the polymer, etc., a further preferred embodiment of the present invention is to add a second polymerization monomer CHfCR^ to the polymerization reaction system. R ^{2 is} subjected to a polymerization 240 reaction.

245 As a preferred embodiment of the present invention, the starting materials for the polymerization: the reactive sulfonate surfactant, the polymerizable monomer and the crosslinking agent are added in one portion, dropwise or stepwise. The polymerization monomer described herein is a combination of a methyl acrylate monomer or a methyl acrylate monomer and a second monomer.

Further preferably, 1/5 to 1/3 of the raw material (by weight) of the polymerization reaction is first added, and after the polymerization reaction is carried out for a certain period of time, the remaining polymerization raw materials are added dropwise or stepwise.

250 The polymerization time is preferably completed to complete the polymerization. Usually 4-36 hours, preferably 8 to 24 hours.

The polymerization temperature is 50 to 90 ° C, preferably 55 to 70 ° C.

Preferably, distilled water and polyvinyl alcohol are added to the reaction apparatus, and the temperature is raised to 85 to 95 ° C. After the polyvinyl alcohol is completely dissolved, it is cooled to 55 to 70 ° C, and then the polymerization raw material is further added to carry out polymerization.

The colloidal protective agent of the present invention is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone 255, and is preferably polyvinyl alcohol. The amount of the colloidal protective agent is 5 to 30%, preferably 10 to 25%, based on the total mass of the polymerization monomer.

The crosslinking agent is a polymerizable monomer having two or more double bonds, such as divinylbenzene or trimethylol. 0%, 0%, preferably 0. 0~7. 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0%, 0% .

至1. The total weight of the polymerized monomer is 0.1% by weight of the total weight of the polymerized monomer. The initiator is a commonly used initiator for the polymerization, such as ammonium persulfate, potassium persulfate, hydrogen peroxide, azobisisobutyl hydrazine and the like. 〜 0. 0%, preferably 0. 5~1. 0%. The ionic polymer/ceramic filler composite film material is composed of acrylate-based polymer colloidal particles having a sulfonate group on the surface and a ceramic filler. The polymer is preferably an acrylate-based polymer having a solvent solubility parameter similar to that used in the electrolyte, and the strong polar group on the surface of the ionic polymer/ceramic filler composite membrane colloidal particles and the non-aqueous electrolyte of the super-265 electrolyte form chemistry. The cooperation ensures that the ionic polymer membrane material of the invention has good compatibility with the electrolyte, and achieves good liquid absorption and liquid retention ability.

As a preferred embodiment of the present invention, the polymer colloidal particles having a sulfonate group on the surface have an average particle diameter ranging from 10 nm to 1.0. The particle size range of the ceramic filler particles ΙΟηιι! ~ 5. 00; Preferably, the colloidal particles have an average particle size ranging from 20 to 200 nm, and the ceramic filler particles have an average particle size range of 20 nn! 〜 0. 5 ; more preferably 20 nm to 200 nm.

270 The ionic polymer/ceramic filler composite film is prepared by the following method:

1. Firstly synthesize a polymer colloidal emulsion containing an anionic group on the surface, add a colloidal protective agent and distilled water to the reaction flask, heat and stir until completely dissolved; and then constant the reactor temperature to a desired reaction temperature of 50 to 90 ° C, Preferably, the reaction type sulfonate surfactant is added with methyl acrylate and the second monomer and the crosslinking agent at a time of 60 to 70 ° C, and then the initiator is added to initiate polymerization, or 1/5 to 1 may be added first. /3 reactive sulfonate surfactant with methyl acrylate,

275 Subsequently, the remaining reactive sulfonate surfactant is added dropwise or stepwise to the methyl acrylate and the second monomer and the crosslinking agent, and the polymerization is carried out for 4 to 36 hours, preferably 8 to 24 hours.

2. Preparation of pre-dispersed ceramic filler slurry, adding ceramic filler and dispersant in distilled water, stirring and dispersing uniformly, then further grinding and dispersing by using agitating ball mill, grinding and dispersing time plume for 2~10 hours, preferably 3~5 The milled slurry was then filtered through a <200 mesh screen to remove unmilled larger particles.

280 3. Add a predetermined amount of pre-dispersed ceramic filler slurry to the synthesized polymer colloidal emulsion, and mix the polymer colloidal emulsion and the ceramic filler slurry with agitation and dispersion equipment, stir and disperse uniformly, and then cast. The coating method is coated on a plastic base tape, such as a PET (polyethylene terephthalate) base tape, and after drying the moisture, it is peeled off to obtain an ionic polymer/ceramic filler composite film.

The reactive sulfonate surfactant is a vinyl sulfonate, an allyl sulfonate, a methallyl sulfonate,

285 allyloxyhydroxypropyl sulfonate, hydroxypropyl sulfonate methacrylate, 2-acrylamido-2-methylpropane sulfonate, benzene One or more of the ethylene sulfonates are used in combination; wherein the cation is lithium ion, sodium ion or potassium ion, and the amount is 2 to 50%, preferably 2 to 10%, based on the total weight of the polymerization monomer.

The colloidal protective agent according to step 1 is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone, and preferably polyvinyl alcohol. The amount of the colloidal protective agent is 5 to 30% by weight based on the total weight of the polymerization monomer, preferably 10 to 25% by 290.

The ceramic filler dispersant of the step 2 is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone, preferably polyvinyl alcohol. In the ceramic filler slurry, the content of the ceramic filler is 80 to 95%, the content of the dispersant is 5 to 20%, and the solid content of the slurry is 20 to 50%.

The polymer colloid which is a preferred embodiment of the present invention has a methyl acrylate content of 40 to 80%.

295 The second polymerizable monomer is CHfCRiR wherein Rf—H or —CH ₃ ; R ₂ = _C ₆ H ₅ , _OCOCH ₃ ,

— CN, _C ₄ H ₆ ON, — C ₂ H ₃ C0 ₃ , —COO(CH ₂ )nCH ₃ , n is 0-14.

The second monomer is used in combination of any one or more of the above monomers in an amount of 2 to 50%, preferably 2 to 10% based on the total mass of the polymerization monomer.

The crosslinking agent is a polymerizable monomer having two or more double bonds, such as divinylbenzene, trimethylol 300 propane triacrylate, dipropylene adipate, methylene Bisacrylamide or the like is used in an amount of from 2.0 to 10.0% by weight based on the weight of the monomer.

The initiator is a water-soluble initiator such as ammonium persulfate, potassium persulfate, hydrogen peroxide or azobisisobutylphosphonate, and is used in an amount of 0.2 to 1.0% by weight based on the weight of the monomer.

As a preferred embodiment of the present invention, the starting materials for the polymerization: the reactive sulfonate surfactant, the polymerization monomer and the crosslinking agent are added in one portion, dropwise or stepwise. The polymerization monomer described herein is a combination of a methyl acrylate 305 monomer or a methyl acrylate monomer and a second monomer.

The ceramic filler is a metal oxide and a metal composite oxide, and has the general formula NzMxOy, wherein N is an alkali metal or alkaline earth metal element, M is a metal element, Z is 0 to 5, and X is 1 to 6, y is 1 to 15. For example: A1 ₂ 0 ₃ , Si0 ₂ , 310 Li ₄ Ti ₅ 0 ₁₂ .

The average particle size of the ceramic filler (D50) is preferably 10 nn! ~ 5.0, better for 20 nn! ~ 0.5 , The preferred ceramic filler is A1 ₂ 0 ₃ and the average particle diameter (D50) is 20 nm to 200 nm. The following are specific examples. 315 Example 1 In a four-port reaction vessel with condensed water, 1000 g of distilled water and 51 g of polyvinyl alcohol were added, and then the temperature was raised to 92 ° C, stirred and dissolved. After the polyvinyl alcohol was completely dissolved, it was cooled to 60 ° C, and 156 g of acrylic acid was added. Methyl ester (MA) monomer, 10 g of sodium allyloxyhydroxypropyl sulfonate (AHPS) and 10 g of cross-linking agent methylene bis acrylamide were stirred for 1 h, and polymerization was initiated by adding 2 g of ammonium persulfate. After the reaction was carried out for 6 hours, Further, 100 g (MA) and 5 g of AHPS were added, and 1.5 g of ammonium persulfate was further added for further polymerization for 10 hours to obtain a white polymer colloidal emulsion having a solid content of 23.9%, and the monomer conversion rate was 96%.

The synthesized polymer colloidal emulsion had a gel particle average particle diameter (D50) of 1.62 as measured by a laser particle size analyzer.

The prepared polymer colloidal emulsion was coated on a PET base tape, and after drying the moisture, an ionic polymer film having a thickness of 20 to 25 m was obtained, and the particle size of the colloidal particles was observed by scanning electron microscopy to be in the range of 80 to 100 nm.

325 Figure 1 is a schematic representation of polymer colloidal particles containing a sulfonate group on a single surface, a for the sulfonate group and b for the polymer colloidal particles bearing a sulfonate group on the surface. Figure 2 is a schematic representation of a polymer colloidal emulsion containing a sulfonate group on the surface. Figure 3 is a schematic representation of an ionic polymer film composed of polymer colloidal particles having a sulfonate group on the surface.

Example 2 In a four-port reaction vessel with condensed water, 1000 g of distilled water and 51 g of polyvinyl alcohol were added, and then the temperature was raised to 92 ° C, and the mixture was stirred and dissolved. After the polyvinyl alcohol was completely dissolved, it was cooled to 60 ° C, and 156 g of acrylic acid was added. Methyl ester (MA) monomer, 10 g of 2-acrylamido-2-methylpropane sulfonate (AMPS) and 10 g of crosslinker methylene bis acrylamide were stirred for 1 h, and 2 g of ammonium persulfate was added to initiate polymerization. After the hour, 100 g (MA) and 5 g of AMPS were further added, and 1.5 g of ammonium persulfate was further added for further polymerization for 10 hours to obtain a white polymer colloidal emulsion.

The prepared polymer colloidal emulsion was coated on a PET base tape, and after drying the moisture, an ionic polymer film having a thickness of 20 to 25 m thick was obtained, and the particle size of the colloidal particles was observed by scanning electron microscopy to be in the range of 80 to 100 nm.

Example 3 In a four-port reaction vessel with condensed water, 1000 g of distilled water and 51 g of polyvinyl alcohol were added, and then the temperature was raised to 92 ° C, stirred and dissolved. After the polyvinyl alcohol was completely dissolved, it was cooled to 60 ° C, and 156 g of acrylic acid was added. The ester (MA) monomer, 8 g of allyl sulfonate (SAS) and 10 g of crosslinker methylene bis acrylamide were stirred for 1 h, and 2 g of ammonium persulfate was added to initiate polymerization. After 340 reaction for 6 hours, 100 g ( MA) and 4 g of SAS were simultaneously added with 1.5 g of ammonium persulfate to continue polymerization for 10 hours to obtain a white polymer colloidal emulsion.

The prepared polymer colloidal emulsion was coated on a PET base tape, and after drying the moisture, an ionic polymer film having a thickness of 20 to 25 μm was obtained, and the particle diameter of the colloidal particles was observed by a scanning electron microscope to be in the range of 40 to 60 nm. Example 4

345 In a four-port reaction vessel with condensed water, add 1000 g of distilled water and 51 g of polyvinyl alcohol, then raise the temperature to 92 ° C, stir to dissolve, and after the polyvinyl alcohol is completely dissolved, cool to 60 ° C, and add 156 g of methyl acrylate ( MA) monomer, 8g allyl sulfonate (SAS) and 10g of cross-linking agent dipropylene diacrylate were stirred for 1h, 2g ammonium persulfate was added to initiate polymerization, after 6 hours of reaction, 100g (MA) and then added 4 g of SAS, while adding 1.5 g of ammonium persulfate to continue polymerization for 10 hours, gave a white polymer colloidal emulsion.

The polymer coated colloidal emulsion 350 produced in the baseband PET, after drying the water, a thickness of 20~25 μ πι ionic polymer thick film, using a particle size range of colloidal particles in scanning electron microscope 4 (T60n _m Example 5

The polymer colloidal emulsion and the ionic polymer membrane of this example were prepared in the same manner as in Example 4 except that 25 g of the second monomer acrylamide (CH ₂ CHCONH ₂ ) was added.

355 Example 6

The polymer colloidal emulsion and ionic polymer film of this example were prepared in the same manner as in Example 4 except that 25 g of the second monomer acrylonitrile (CH ₂ CHCN) was added.

Example 7

The polymer colloidal emulsion and the ionic polymer membrane of this example were prepared in the same manner as in Example 4, except that the addition of 25 g of the second monomer butyl acrylate (CH ₂ CHCOOCH ₂ CH ₂ CH ₂ CH ₃ ) was increased by 360. .

Example 8

The polymer colloidal emulsion and the ionic polymer film of this example were prepared in the same manner as in Example 4 except that 25 g of the second monomer vinyl vinyl carbonate (CH ₂ CHC ₂ H ₃ C0 ₃ ) was added.

The ceramic filler slurry used in the following examples was prepared by the following method:

Preparation of 365 A1 ₂ 0 ₃ slurry: Polyvinyl alcohol having a degree of polymerization of 1700 and a degree of hydrolysis of 99% was added to 1000 parts of distilled water.

20 parts, then heated to 90~94 ° C, dissolved polyvinyl alcohol under stirring for 3 hours, then cooled to room temperature and then added 200 parts of A1 ₂ 0 ₃ with an average particle diameter (D50) of 36 nm, stirred and dispersed evenly, and then The dispersion was further milled using a stirring ball mill, and the milling dispersion time was 4 hours. The milled slurry was then filtered through a <200 mesh screen to remove unmilled larger particles.

370 During the processing of A1 ₂ 0 ₃ slurry, the content of A1 ₂ 0 ₃ in the finally obtained slurry is due to the loss of moisture evaporation.

21.5%. Example 9 Preparation of ionic polymer/ceramic filler composite membrane

100 g of the polymer colloidal emulsion prepared in Example 1 and 12.4 g of the A1 ₂ 0 ₃ slurry were placed in a three-necked flask for 10 hours to obtain a uniformly dispersed polymer colloidal emulsion and A1 ₂ 0 ₃ slurry mixture slurry. Then, the mixture slurry is coated on a PET (polyethylene terephthalate) base tape by a cast coating method 375, and after drying the water, it is peeled off to obtain an ionic polymer having a thickness of 20 to 25 μm. /Α1 ₂ 0 ₃ composite film, wherein Α1 ₂ 0 ₃ accounts for 10% by mass in the film. Example 10 Preparation of Ionic Polymer/Ceramic Filler Composite Film

The ionic polymer/Α1 ₂ ₃ composite film of this embodiment was prepared in the same manner as in Example 9, except that the Α1 ₂ 0 ₃ slurry plus 380 was 19.6 g, wherein A1 ₂ 0 _{3 was} in the film. The mass percentage is 15%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 20 to 25 μm.

Example 11 Preparation of ionic polymer/ceramic filler composite membrane

Example embodiment of the present ionic polymer / Α1 ₂ 0 ₃ Composite Membrane prepared in Example 9 in the same, the only difference is, Α1 ₂ 0 ₃ is added to 27.8 g of the slurry, wherein, A1 ₂ 0 ₃ film in proportion The mass percentage is 20%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 385 degrees of 20 to 25 μm.

Example 12 Preparation of Ionic Polymer/Ceramic Filler Composite Film

Example embodiment of the present ionic polymer / Α1 ₂ 0 ₃ Composite Membrane prepared in Example 9 in the same, the only difference is, Α1 ₂ 0 ₃ is added to 37.1 g of the slurry, wherein, A1 ₂ 0 ₃ film in proportion The mass percentage is 25%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 20 to 25 μm.

390 Example 13 Preparation of ionic polymer/ceramic filler composite membrane

Example embodiment of the present ionic polymer / Α1 ₂ 0 ₃ Composite Membrane prepared in Example 9 in the same, the only difference is, Α1 ₂ 0 ₃ is added to 47.6 g of the slurry, wherein, A1 ₂ 0 ₃ film in proportion The mass percentage is 30%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 20 to 25 μm.

Example 14 Preparation of ionic polymer/ceramic filler composite membrane

395 cases of embodiment of ionic polymer / Α1 ₂ 0 ₃ Composite Membrane prepared in Example 9 in the same, the only difference is, Α1 ₂ 0 ₃ is added to the slurry 74.1 g, wherein, A1 ₂ 0 ₃ film in Suo The mass percentage is 40%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 20 to 25 μm.

Example 15 Preparation of ionic polymer/ceramic filler composite membrane

The ionic polymer/Α1 ₂ _{3 3} composite film of this embodiment is prepared in the same manner as in the embodiment 9, except that the Α1 ₂ 0 ₃ slurry is added. The 400-in is 111.2 g, wherein A1 ₂ 0 ₃ accounts for 50% by mass in the film, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 20 to 25 μm.

Example 16 Preparation of ionic polymer/ceramic filler composite membrane

Example embodiment of the present ionic polymer / Α1 ₂ 0 ₃ Composite Membrane prepared in Example 9 in the same, the only difference is, Α1 ₂ 0 ₃ is added to 166.7 g paste, wherein, A1 ₂ 0 ₃ film in proportion The mass percentage is 60%, and the ionic polymer/A1 ₂ 0 ₃ composite film has a thickness of 405 degrees of 20 to 25 μm.

Test example 1

The ionic polymer film prepared in Examples 1 to 8 was immersed in an electrolyte solution composed of ethylene carbonate/diethyl carbonate/dimethyl carbonate and LiPF ₆ to be used after the ionic polymer film sufficiently absorbed the electrolyte solution. The chemical conductivity meter was used to measure the ionic conductivity and the absorption of the electrolyte solution. The ionic conductivity and the absorption of the electrolyte solution were also measured under the same conditions of commercial polypropylene and polypropylene microporous membranes. Listed in Table 1.

After the ionic polymer film is immersed in the electrolyte solution, the scanning electron micrograph of the typical microscopic morphology of the film is shown in Fig. 4. The microstructure of the ionic polymer film of the present invention remains in the form of colloidal particles after being impregnated with the electrolyte solution. Test example 2

The ionic polymer films obtained in Examples 1 to 8 and commercial polypropylene and polypropylene microporous films were heated to 130 ° C and 415 150 ° C, and the heat shrinkage ratio thereof was measured. The test results are shown in Table 1.

Table 1. Electrolyte absorption, ionic conductivity and thermal shrinkage of the ionic polymer membrane of the present invention

The comparative data from Table 1 shows that the ionic polymer film of the present invention has a small heat shrinkage rate, and the polyethylene and polypropylene microporous films have undergone severe shrinkage or melting at the same temperature, for example, 150 °C. Test Example 3

420 The ionic polymer film prepared in Example 5 was assembled into a button cell preparation process familiar to those skilled in the art.

2032 button battery, which uses LiMn ₂ 0 ₄ as the positive electrode material, lithium metal as the negative electrode material and electrolyte solution composed of ethylene carbonate / diethyl carbonate / dimethyl carbonate / LiPF ₆ , 2032 button lithium battery in The charge and discharge performance test was carried out under the condition of 0.2 C rate.

Figure 5 is a graph of the charge and discharge of a lithium battery of an ionic polymer film, which shows that the ionic polymer film is used as a battery separator, and the 425 battery has good charge and discharge performance.

Fig. 6 is a graph showing the capacity retention ratio as a function of the number of cycles during the charge and discharge cycle of the lithium battery of the ionic polymer film, which confirmed that the battery of the ionic polymer film has good charge and discharge cycle performance.

Test example 4

The ionic polymer/A1 ₂ ₃ composite film prepared in Examples 9 to 16 was immersed in an electrolyte solution composed of ethylene carbonate/diethyl carbonate/dicarbonate 430 methyl ester and LiPF ₆ until the composite film sufficiently absorbed the electrolyte. After the solution, the amount of absorption of the electrolyte solution was measured, and the ionic conductivity was measured using an electrochemical impedance meter. The test results are shown in Table 2.

Test example 5

The ionic polymer/A1 ₂ ₃ composite film obtained in Examples 9 to 16 was heated to 130 ° C, and the heat shrinkage ratio thereof was measured. The test results are shown in Table 2.

435 Table 2. Electrolyte absorption, ionic conductivity and thermal shrinkage of ionic polymer/A1 ₂ 0 ₃ composite membrane

The data in Table 2 shows that the ionic polymer/A1 ₂ ₃ composite film of the present invention gradually decreases in thermal shrinkage rate with the increase of A1 ₂ 0 ₃ , and the electrical conductivity exhibits an optimum value at about 30% of the ceramic filler. After more than 50%, the conductivity decreases. Therefore, from the above data, the content of the ceramic filler should not exceed 60%. Preferably, it is 15-50%, more preferably 440 is 25-30%.

Test example 6

The ionic polymer and ionic polymer/A1 ₂ ₃ composite film prepared in Example 1 and Example 13 were assembled into a 2032 button battery according to a button cell preparation process familiar to those skilled in the art, and the battery was LiMn ₂ 0 . ₄ is a positive electrode material, metal lithium is composed of an anode material and an electrolyte solution composed of ethylene carbonate/diethyl carbonate/dimethyl carbonate/LiPF6,

The 445 2032 button lithium battery was tested for charge and discharge performance at 0.2C rate.

Figure 7 is a lithium battery discharge curve of the ionic polymer film and the ionic polymer/A1 ₂ ₃ composite film prepared in Example 1 and Example 13, which shows that the ionic polymer/A1 ₂ 0 ₃ composite film is more than the ionic polymer film. has better charge-discharge characteristics, under the same conditions, the battery capacity g g manganese lithium ion polymer film material only 107mAh / g, and the ionic polymer / A1 ₂ battery lithium manganate material ₀₃ of the composite film The capacity reaches 115 mAh/g. The increase in the gram capacity of lithium manganate material is supported by

The presence of a heterophase interface between the 450 A1 ₂ 0 ₃ and the polymer colloid helps to increase the ionic conductivity of the ionic polymer/A1 ₂ ₃ composite film.

8 is a fifth and 100th charge-discharge curve of a lithium battery of the ionic polymer/A1 ₂ ₃ composite film prepared in Example 13, and after 100 charge-discharge cycles, the capacity retention rate is 98 of the initial capacity. %, exhibits excellent charge and discharge cycle performance.

455 Figure 9 is a scanning electron micrograph of the ionic polymer/A1 ₂ ₃ composite film prepared in Example 13, which shows that the composite film is still composed of colloidal particles and ceramic filler particles after the electrolyte solution is impregnated.

Claims

claims

1. An ionic polymer membrane material, characterized by: It is composed of polymer colloid 460 particles with sulfonate groups on the surface.

2. The ionic polymer membrane material according to claim 1, characterized in that: the polymer colloid particles are methyl acrylate polymer colloid particles.

3. The ionic polymer membrane material according to claim 2, characterized in that: the sulfonate group is vinyl sulfonate, allyl sulfonate, methylallyl sulfonate, Allyloxyhydroxypropyl sulfonate, hydroxymethacrylate

465 One or more of propyl sulfonate, 2-acrylamido-2-methylpropane sulfonate, and styrene sulfonate.

4. The ionic polymer membrane material according to any one of claims 1 to 3, characterized in that: after the polymer colloidal emulsion is film-formed, the particle size range of the colloidal particles is 10 nm~1.0 m, preferably 20~ 200nm.

5. The ionic polymer membrane material according to claim 4, characterized in that: the thickness of the ionic polymer membrane is 10~40 m.

470 6. Preparation method of ionic polymer membrane material, characterized by: During the polymerization reaction to form polymer colloidal particles, a reactive sulfonate surfactant is added as an emulsifier, and the synthetic surface has a sulfonate group. The acrylic polymer colloidal emulsion is formed into a film and dried.

7. The preparation method of ionic polymer membrane material according to claim 6, characterized in that: the reactive sulfonate surfactant is vinyl sulfonate, allyl sulfonate, methylallyl sulfonate Sulfonate, Allyloxyhydroxypropyl Sulfonate

475 acid salt, methacrylic acid hydroxypropyl sulfonate, 2-acrylamido-2-methylpropane sulfonate, styrene sulfonate, or a mixture of one or more thereof; wherein the cation is lithium ion , sodium ions or potassium ions.

8. The method for preparing an ionomer membrane material according to claim 7, characterized in that: the ionomer membrane is prepared by the following method:

a. Synthesis of polymer colloidal emulsion: Add the colloidal protective agent and distilled water into the reaction bottle, heat and stir until completely dissolved, add reactive sulfonate surfactant, polymerization monomer and cross-linking agent and mix evenly. Then an initiator is added for polymerization reaction to obtain a polymer colloidal emulsion;

b. Polymer colloidal emulsion, coated on the plastic base tape, dried and peeled off.

9. The method for preparing an ionic polymer membrane material according to claim 8, characterized in that: the polymerization reaction monomer is methyl acrylate.

485 10. The method for preparing an ionic polymer membrane material according to claim 9, characterized in that: a second polymerized monomer CH^CRiR ² is also added to the polymerization reaction system to perform the polymerization reaction; Wherein, Ι^=_H or _CH ₃ ;

R ² =—C ₆ H ₅ , — OCOCH ₃ , — CN, — C ₄ H ₆ ON , — C ₂ H ₃ C0 ₃ , -COO (CH ₂ ) _n CH ₃ , n is 0~

14, any one or a mixture of more of them is used.

490 1 1. The preparation method of ionomer membrane material according to claim 9, characterized in that: the amount of the second monomer is 2~50% of the total weight of polymerized monomers, preferably 2~10% .

12. The preparation method of ionomer membrane material according to any one of claims 8-11, characterized in that: the colloidal protective agent is polyvinyl alcohol, polyethylene oxide, polyacrylate, polyvinyl alcohol One type of pyrrolidone is preferably polyvinyl alcohol.

495 13. The preparation method of ionomer membrane material according to claim 12, characterized in that: the amount of colloidal protective agent is 5~30% of the total weight of polymerization monomers.

14. The method for preparing an ionic polymer membrane material according to any one of claims 8 to 13, characterized in that: the cross-linking agent is polymerizable containing two double bonds or more than two double bonds. monomer.

15. The preparation method of ionomer membrane material according to claim 14, characterized in that: the 500% cross-linking agent is divinylbenzene, trimethylolpropane triacrylate, and dipropylene adipate 0%。 , methylene bisacrylamide, etc., the amount of which is 2. 0~10. 0% of the total weight of polymerization monomers, preferably 5. 0~7. 0%.

16. Lithium secondary battery, characterized in that: it is prepared by using the ionic polymer membrane material described in any one of claims 1-5 as a separator or by the method described in any one of claims 6-15. The ionic polymer membrane material is the separator.

17. An ionic polymer/ceramic filler composite membrane material, characterized in that: it is composed of acrylate polymer colloid particles with sulfonate groups on the surface and ceramic filler particles dispersed therein.

18. The ionic polymer/ceramic filler composite membrane material according to claim 17, characterized in that: the polymer colloid particles are methyl acrylate polymer colloid particles, and the ceramic filler particles are metal oxides or Metal composite oxide particles.

19. The ionic polymer/ceramic filler composite membrane material according to claim 18, characterized in that: the mass percentage of ceramic 510 filler particles in the composite membrane material is 10-60%, preferably 15 -50%, more preferably 25-40%.

20. The ionic polymer membrane material according to claim 18, characterized in that: the sulfonate group is vinyl sulfonate, allyl sulfonate, methylallyl sulfonate, One or more of allyloxy hydroxypropyl sulfonate, methacrylic acid hydroxypropyl sulfonate, 2-acrylamido-2-methylpropane sulfonate, and styrene sulfonate.

515 21. The ionic polymer/ceramic filler composite membrane material according to any one of claims 17 to 19, characterized by It is: In the ionic polymer/ceramic filler composite membrane material, the average particle size range of the colloidal particles is 10 nm ~ 1. 0, and the average particle size range of the ceramic filler particles is 10 _nm ~ 5. 00 m _; preferably, the colloid particles The average particle size range of the particles is 20~200nm, and the average particle size range of the ceramic filler particles is 20 nn! ~0.5; more preferably 20nm~200nm.

22. The ionic polymer/ceramic filler composite membrane material according to claim 20, characterized in that: the thickness of the 520 ionic polymer/ceramic filler composite membrane is 10~40.

23. The preparation method of ionic polymer/ceramic filler composite membrane material according to claim 17, characterized in that: during the polymerization reaction to form polymer colloidal particles, a reactive sulfonate surfactant is added as an emulsifier. , synthesize an acrylate polymer colloidal emulsion with sulfonate groups on the surface, then add metal oxide or metal composite oxide particles, mix evenly, form a film, and dry.

525 24. The preparation method of ionic polymer/ceramic filler composite membrane material according to claim 23, characterized in that: the reactive sulfonate surfactant is vinyl sulfonate, allyl sulfonate, Methallyl Sulfonate, Allyloxy Hydroxypropyl Sulfonate, Methacrylic Acid Hydroxypropyl Sulfonate, 2-Acrylamido-2-Methylpropane Sulfonate, Styrene Sulfonate One or more of them are used in mixture; among them, the cation is lithium ion, sodium ion or potassium ion.

25. The method for preparing the ionic polymer/ceramic filler composite membrane material according to claim 23, characterized in that: through the following steps:

a. Synthesis of polymer colloidal emulsion: Add the colloidal protective agent and distilled water into the reaction bottle, heat and stir until completely dissolved, add the reactive sulfonate surfactant, polymerization monomer and cross-linking agent and mix evenly, then add The polymerization reaction of the initiator produces a polymer colloidal emulsion;

b. Preparation of ceramic filler slurry: Add ceramic filler and dispersant to distilled water. After dispersing evenly, use a 535 ball mill to further grind and disperse, and pass through a 200-mesh sieve;

c. Add the ceramic filler slurry prepared in step b to the polymer colloidal emulsion in step a, disperse it evenly, apply it on the plastic base tape, dry it and peel it off to obtain the result.

26. The method for preparing the ionic polymer/ceramic filler composite membrane material according to claim 25, characterized in that: the polymerization monomer is methyl acrylate.

540 27. The method for preparing the ionic polymer/ceramic filler composite membrane material according to claim 26, characterized in that: a second polymerization monomer CH^CRiR ² is also added to the polymerization reaction system to perform the polymerization reaction;

Wherein, Ι^=_H or _CH ₃ ;

14, any one or a mixture of more of them is used. 545

28. The preparation method of ionic polymer/ceramic filler composite membrane material according to claim 27, characterized in that: the second monomer dosage is 2~50% of the total weight of polymerized monomers, preferably 2~ 10%.

29. The method for preparing the ionic polymer/ceramic filler composite membrane material according to any one of claims 25 to 28, characterized in that: the colloidal protective agent in step 1 is polyvinyl alcohol, polyethylene oxide, polyethylene oxide, One of acrylate and polyvinylpyrrolidone, preferably polyvinyl alcohol; the amount of colloidal protective agent is the total weight of polymerization monomers

550 5~30%; A further preferred solution is that the dispersant is one of polyvinyl alcohol, polyethylene oxide, polyacrylate, and polyvinylpyrrolidone, preferably polyvinyl alcohol; in the ceramic filler slurry , the content of ceramic filler is 80~95%, the content of dispersant is 5~20%, and the solid content of slurry is 20~50%.

30. Lithium secondary battery, characterized in that: it uses the ionic polymer/ceramic filler composite membrane material as described in any one of claims 17-22 as the separator or uses the ionic polymer/ceramic filler composite membrane material as described in any one of claims 23-29. Ionic polymers prepared by

555/Ceramic filler composite membrane material is used as diaphragm.