CN104218205B - Heat-resisting porous isolating membrane and its manufacture method - Google Patents

Abstract

The present invention provides a kind of heat-resisting porous isolating membrane and preparation method thereof, and heat-resisting porous isolating membrane includes porous substrate and composite coating.Composite coating is arranged on an at least surface of porous substrate.Wherein, composite coating is made up of hydrophilic macromolecule with silica, and composite coating has interpenetrating type macromolecule network structure (Interpenetrating polymer network, IPN).The manufacture method of heat-resisting porous isolating membrane provided by the present invention, may be such that the composite coating on porous substrate has interpenetrating type macromolecule network structure.Heat-resisting porous isolating membrane proposed by the present invention, with good heat resistance and electrolyte adsorption capacity, good heat resistance can be prevented effectively from there is severe heat shrinkage or melt fracture in porous separation film, cause battery short circuit or blast.And preferably electrolyte absorption affinity, it is possible to decrease the interior resistance of battery is lifting battery efficiency.

Description

Heat-resistant porous separator and manufacturing method thereof

technical field

The invention relates to a heat-resistant porous isolation membrane, and in particular to a porous isolation membrane applied to a lithium ion battery and a preparation method thereof.

Background technique

The porous separator is a polymer film used in lithium batteries, which is interposed between the positive and negative electrodes of the lithium battery to prevent the short circuit of the electrodes due to physical contact. At the same time, the microporous properties of the separator allow free ions in the electrolyte to pass through it, allowing the battery to generate voltage. However, when the heat resistance of the separator is not good, it will cause the separator to shrink easily after being heated, resulting in direct contact between the positive and negative electrodes of the battery, thereby causing a short circuit.

In order to improve the heat resistance of the separator, the general manufacturing method is to mix heat-resistant inorganic particles with an adhesive and then coat them on the surface of the porous separator. However, this method is very likely to cause the inorganic particles to fall off due to poor adhesion between the inorganic particles and the separator, resulting in a decrease in the performance of the porous separator and insufficient safety of the battery. Furthermore, the size of the inorganic particles is larger than the pores of the isolation film, so they can only be distributed on the surface of the porous isolation film, slowing down the speed of heat conduction to the isolation film, but the isolation film will still shrink when heated, causing a short circuit risk.

On the other hand, the separator is mostly made of non-polar materials such as polyolefin, so the adsorption capacity for the electrolyte is not good. In addition, although the separator coated with inorganic particles can absorb the electrolyte by utilizing the capillary phenomenon caused by particle stacking, the adsorption capacity for the electrolyte is limited.

Contents of the invention

In view of the poor heat resistance, wettability and flexibility of the separator in the battery above, the present invention proposes a heat-resistant porous separator, which has good heat resistance and electrolyte adsorption capacity. The heat-resistant porous isolation membrane includes a porous substrate and a composite coating. The composite coating is an interpenetrating polymer network (IPN) composed of hydrophilic polymer and silicon dioxide. The manufacturing method of the heat-resistant porous isolation membrane provided by the invention can make the composite coating on the porous substrate have an interpenetrating polymer network structure. At high temperature, the inorganic coating in this composite coating can improve the shrinkage of the separator when it is heated, and avoid the severe thermal shrinkage or melt rupture of the porous separator when the internal temperature of the battery is too high, resulting in short circuit or explosion of the battery . In addition, the hydrophilic polymer in the composite coating can increase the hydrophilicity of the surface of the porous separator, increase the electrolyte it absorbs, and reduce the internal resistance of the battery to improve battery performance. At the same time, it can improve the flexibility of the composite coating and avoid cracking of the coating.

The invention provides a heat-resistant porous isolation membrane, which includes a porous substrate and a composite coating. The composite coating is disposed on at least one surface of the porous substrate. The composite coating is an interpenetrating polymer network (IPN) composed of silica and hydrophilic polymers.

According to an embodiment of the present invention, the material of the porous substrate is high-density polyethylene, polypropylene, polyvinyl fluoride, polyvinyl chloride, polyester, polyamide, non-woven fabric or a combination thereof.

According to an embodiment of the present invention, the silica polymer network structure in the interpenetrating polymer network structure is formed by a silica precursor through hydrolysis and condensation reaction.

In the heat-resistant porous isolation membrane, the weight ratio of the hydrophilic polymer to the silicon dioxide precursor is between 0.008 and 1.5.

According to an embodiment of the present invention, the above-mentioned hydrophilic polymer is ethylene-vinyl alcohol copolymer (Ethylenevinyl alcohol polymer, EVOH), polyvinyl alcohol (Polyvinylalcohol, PVA), or any combination of the above materials.

According to an embodiment of the present invention, the composite coating further includes a dispersant.

According to an embodiment of the present invention, the above-mentioned dispersant is 3-glycidoxypropyl trimethoxysilane (3-glycidoxypropyl trimethoxysilane, GLYMO), vinyltrimethoxysilane (Vinyltrimethoxysilane, VTMO), 3-aminopropyl triethoxysilane 3-amionpropyltrimethoxysilane (AMEO), 3-(methacryloyloxy)propyltrimethoxysilane (3-Methacryloxypropyltrimethoxysilane, MEMO) or any combination of the above materials.

The invention proposes a method for manufacturing a heat-resistant porous isolation membrane, which includes the following steps: providing a porous substrate; adding 0.2 to 1.5 parts by weight of a hydrophilic polymer to 90 to 98 parts by weight of a solvent , to form a reaction solution; add 1 to 25 parts by weight of silicon dioxide precursor to the above reaction solution to form a mixed solution; add aqueous hydrochloric acid to the above mixed solution for hydrolysis and condensation reaction to form a transparent and clear solution; coating the transparent and clear solution on at least one surface of the porous substrate to form a composite coating; and drying the porous substrate with the composite coating to prepare a heat-resistant porous isolation film.

According to an embodiment of the present invention, the material of the porous substrate is high-density polyethylene, polypropylene, polyvinyl chloride, polyvinyl fluoride, polyester, polyamide, non-woven fabric or any combination of the above materials.

According to an embodiment of the present invention, the above-mentioned hydrophilic polymer is ethylene-vinyl alcohol copolymer (Ethylenevinyl alcohol polymer, EVOH), polyvinyl alcohol (Polyvinylalcohol, PVA), or any combination of the above materials.

According to an embodiment of the present invention, the above-mentioned solvent is water, ethanol, isopropanol, methanol or any combination of the above-mentioned materials.

According to an embodiment of the present invention, the silicon dioxide precursor is tetraethoxysilane, tetramethoxysilane, trimethoxysilane or any combination of the above materials.

According to an embodiment of the present invention, before adding the hydrochloric acid aqueous solution to the mixed solution, adding a dispersant to the mixed solution is also included.

According to one embodiment of the present invention, the above-mentioned dispersant is 3-glycidoxypropyl trimethoxysilane (3-glycidoxypropyl trimethoxysilane, GLYMO), vinyltrimethoxysilane (Vinyltrimethoxysilane, VTMO), 3-aminopropyl triethoxysilane 3-amionpropyltrimethoxysilane (AMEO), 3-(methacryloyloxy)propyltrimethoxysilane (3-Methacryloxypropyltrimethoxysilane, MEMO) or any combination of the above materials.

Compared with the prior art, the heat-resistant porous isolation membrane of the present invention forms an interpenetrating polymer network formed by the interaction between the silica precursor and the hydrophilic polymer on the surface of the porous substrate. structure, in which the silica polymer network structure can effectively prevent the shrinkage of the porous separator at high temperature, so as to avoid the serious thermal shrinkage or melting rupture of the porous separator when the internal temperature of the battery is too high, which will cause the battery Short circuit or explosion; the hydrophilic polymer makes the wettability of the porous separator better, which is conducive to the passage of electrolytic heat in the battery, and reduces the internal resistance of the battery to improve battery performance.

Description of drawings

none.

detailed description

In order to make the above-mentioned and other purposes, features, and advantages of the present invention more obvious and understandable, the preferred embodiments are specifically cited below, and are described in detail as follows:

The invention provides a heat-resistant porous isolation membrane, which includes a porous substrate and a composite coating. The composite coating is disposed on at least one surface of the porous substrate. The composite coating is an interpenetrating polymer network (IPN) composed of hydrophilic polymers and silicon dioxide.

In the above heat-resistant porous separator, the material of the porous substrate can be high-density polyethylene, polypropylene, polyester, polyamide or a combination thereof. In a preferred embodiment of the present invention, the porous substrate is a polypropylene (PP) microporous membrane with a thickness of 20 μm.

In the above-mentioned heat-resistant porous isolation membrane, the silica polymer network structure is formed by the silica precursor through hydrolysis and condensation reaction, and the hydrophilic polymer in the heat-resistant porous isolation membrane and the silica precursor The ratio of parts by weight is between 0.008 and 1.5, preferably between 0.01 and 0.6. When the ratio is lower than the above range, the formed composite coating is prone to cracking, and the surface of the formed isolation film is more hydrophobic, so the effect of adsorbing the electrolyte is not good. When the ratio is higher than the above range, the heat resistance of the prepared separator will be poor.

In the above-mentioned heat-resistant porous separator, the hydrophilic polymer can be ethylene-vinyl alcohol copolymer (Ethylenevinyl alcohol polymer, EVOH), polyvinyl alcohol (Polyvinylalcohol, PVA), or a combination of the above materials. In a preferred embodiment of the present invention, the hydrophilic polymer is ethylene-vinyl alcohol copolymer, and its weight average molecular weight is between 10,000 and 500,000. When the weight average molecular weight of the hydrophilic polymer is too large, it is easy to block the pores in the isolation membrane. When the weight-average molecular weight of the hydrophilic polymer is too small, the formed coating will be easily peeled off.

In the above-mentioned heat-resistant porous isolation membrane, the composite coating in the heat-resistant porous isolation membrane also includes a dispersant, which can be 3-glycidoxypropyl trimethoxysilane (3-glycidoxypropyl trimethoxysilane, GLYMO), vinyl trimethoxy Silane (Vinyltrimethoxysilane, VTMO), 3-amionpropyltrimethoxysilane (3-amionpropyltrimethoxysilane, AMEO), 3-(methacryloxy)propyltrimethoxysilane (3-Methacryloxypropyltrimethoxysilane, MEMO) or the above materials The combination. This dispersant is used to improve the distribution uniformity between silica and hydrophilic polymer in the composite coating. And relative to the total of 100 parts by weight of the silicon dioxide precursor and the hydrophilic polymer, the amount of the dispersant added is 15 to 25 parts by weight. In a preferred embodiment of the present invention, the dispersant is 3-glycerolpropyltrimethoxysilane.

The present invention also provides a method for manufacturing a heat-resistant porous isolation membrane, which includes the following steps: providing a porous substrate; adding 0.2 to 1.5 parts by weight of a hydrophilic polymer to 90 to 98 parts by weight of a solvent to form a reaction solution; add 1 to 25 parts by weight of silicon dioxide precursor to the reaction solution to form a mixed solution; add hydrochloric acid aqueous solution to the mixed solution for hydrolysis and condensation reaction to form a transparent clear solution; coating the transparent clear solution on at least one surface of the porous substrate to form a composite coating; and drying the porous substrate with the composite coating to prepare a heat-resistant porous isolation membrane.

In the manufacturing method of the above-mentioned heat-resistant porous isolation membrane, in order to make the silica precursor react to generate silica with a network structure, and form an interpenetrating polymer network structure with the hydrophilic polymer, Therefore, it is necessary to add aqueous hydrochloric acid to carry out the hydrolysis condensation reaction. The weight percent concentration of the above-mentioned hydrochloric acid aqueous solution is 37%, but not limited thereto, in other embodiments of the present invention, the weight percent concentration of the hydrochloric acid aqueous solution added as long as can make the above-mentioned mixed solution form a transparent and clear state after the hydrolysis condensation reaction, That is to say, an interpenetrating polymer network structure is generated. When the amount of the solvent, the silicon dioxide precursor and the hydrochloric acid aqueous solution exceeds or is less than the above-mentioned range, the silicon dioxide precursor will form silicon dioxide particles and cannot form a network structure. Furthermore, in order to improve the hydrophilicity of the surface of the porous isolation membrane and increase the electrolyte solution it adsorbs, it is necessary to add a hydrophilic polymer. Using the manufacturing method proposed by the present invention, silicon dioxide and hydrophilic polymers can be used to form a composite coating, and its interpenetrating polymer network structure can make the porous isolation membrane more heat-resistant, hydrophilic and flexible. . In a preferred embodiment of the present invention, the amount of the hydrophilic polymer used is between 0.2 parts by weight and 1.5 parts by weight, the amount of solvent used is between 90 parts by weight and 98 parts by weight, and silica The usage amount of the precursor is between 2.8 parts by weight and 18 parts by weight.

In the manufacturing method of the above-mentioned heat-resistant porous separator, the material of the porous substrate can be high-density polyethylene, polypropylene, polyvinyl fluoride, polyvinyl chloride, polyester, polyamide, non-woven fabric or a combination of the above materials. In a preferred embodiment of the present invention, the porous substrate is a polypropylene microporous membrane with a thickness of 20 μm and a porosity of 45%.

In the above method for producing a heat-resistant porous separator, the hydrophilic polymer can be ethylene-vinyl alcohol copolymer, polyvinyl alcohol, or a combination of the above materials. In a preferred embodiment of the present invention, the hydrophilic polymer is ethylene-vinyl alcohol copolymer, and its weight average molecular weight is between 10,000 and 500,000.

In the manufacturing method of the above heat-resistant porous separator, the solvent may be water, ethanol, isopropanol, methanol or a combination of the above materials.

In the manufacturing method of the above-mentioned heat-resistant porous isolation membrane, the silica precursor may be tetraethoxysilane (Tetraethyl orthosilicate, TEOS), tetramethoxysilane (Tetramethyl orthosilicate, TMOS, trimethoxy silane) Or a combination of the above materials. In a preferred embodiment of the present invention, the silicon dioxide precursor is tetraethoxysilane.

In the above method for producing a heat-resistant porous separator, before adding the hydrochloric acid aqueous solution to the mixed solution, adding a dispersant to the mixed solution is further included. The dispersant can be 3-glycerylpropyltrimethoxysilane (3-glycidoxypropyltrimethoxysilane, GLYMO), vinyltrimethoxysilane (Vinyltrimethoxysilane, VTMO), 3-aminopropyltriethoxysilane (3-amionpropyltrimethoxysilane, AMEO) , 3-(methacryloyloxy)propyltrimethoxysilane (3-Methacryloxypropyltrimethoxysilane, MEMO) or a combination of the above materials. The dispersant is used to improve the distribution uniformity between organic materials and inorganic materials in the composite coating. And relative to the total of 100 parts by weight of the silicon dioxide precursor and the hydrophilic polymer, the amount of the dispersant added is between 15 and 25 parts by weight. In a preferred embodiment of the present invention, the dispersant is 3-glycerolpropyltrimethoxysilane.

In the manufacturing method of the above-mentioned heat-resistant porous separator, the coating method can be gravure coating (Gravure coating), slot die coating (Slot-Die coating), roll coating (Roll coating), wire bar Wire-Bar coating, Blade coating, Extrusion coating, Dip coating, Spin coating, or inclined plate Coating (Slot-Slidecoating), but not limited thereto.

In the manufacturing method of the above-mentioned heat-resistant porous isolation membrane, the porous substrate with the composite coating is dried, the drying temperature is between 60°C and 120°C, and the drying time is between 0.5 minutes and 10 minutes. In a preferred embodiment of the present invention, the drying temperature is 80° C., and the drying time is 3 minutes.

Finally, the porous isolation membrane prepared by the present invention is characterized according to the following methods, and the evaluation results are shown in Table 1 to Table 2.

Air permeability test: according to the ASTM D-726 specification, use the Gurley air permeability meter to measure the time required for 10c.c.

Heat shrinkage test: Cut the separator to be tested into a size of 10 cm×10 cm, and then measure the length L1 in the machine direction (MD). Then put the isolation film to be tested into an oven with a drying temperature of 150°C and a drying time of 1 hour, measure the length L2 of the isolation film to be tested in the machine direction (MD) after taking it out, and calculate the thermal shrinkage rate . Its calculation formula is (L1-L2)/L1×100%.

Surface energy test: on the surface of the isolation film to be tested, use dyne pens with different surface energies (30-50 dyne/cm) to wipe the surface of the film. When the ink trace does not shrink within 2 seconds, it means that the surface of the film has Good wettability, the next step can be tested with a Dyne pen with higher surface energy. When the ink traces on the surface of the membrane shrink within 2 seconds and appear in the shape of beads, it means that the surface of the isolation membrane has poor wettability for this grade of dyne pen, so the surface of the isolation membrane can be tested by the previous level of dyne The surface energy of the pen. When the surface energy is lower, it means that the surface of the isolation membrane to be tested is more hydrophobic; on the contrary, when the surface energy is higher, it means that the surface of the isolation membrane to be tested is more hydrophilic.

Example 1

0.5 parts by weight of ethylene-vinyl alcohol copolymer (trade name 414077, ethylene content of 27mol%, purchased from U.S. Sigma-Aldrich company) is placed in 95 parts by weight of solvent to form a reaction solution, the solvent is ethanol aqueous solution, ethanol and Water is prepared according to the weight percentage of 60:40. Then, the reaction solution was heated to 95° C., reacted for 2 hours, and cooled to room temperature after forming a transparent and clear reaction solution. Then, 9 parts by weight of tetraethoxysilane was added to the transparent and clear reaction solution, and a mixed solution was formed after uniform stirring, and then 0.2 parts by weight of aqueous hydrochloric acid solution with a weight concentration of 37% was added to the mixed solution for 1 hour of hydrolysis reaction To obtain a transparent and clear coating solution. Finally, the transparent and clear coating solution is applied to both surfaces of polypropylene microporous membrane (trade name D120D, thickness is 20 μm, manufactured by Taiwan Mingji Materials Co., Ltd.) to form a composite coating, and then the porous membrane with composite coating Dry the base material with a drying temperature of 80°C and a drying time of 3 minutes. Finally, a heat-resistant porous isolation membrane is prepared.

Example 2-Example 6

The implementation method of embodiment 2 to embodiment 6 is the same as that of embodiment 1, the difference lies in the composition of ethylene-vinyl alcohol copolymer, tetraethoxysilane and solvent in embodiment 2 to embodiment 6 are different. Please refer to Table 1 for its detailed composition.

Example 7-Example 8

Examples 7 to 8 are implemented in the same way as in Example 1, except that the ethylene-vinyl alcohol copolymer, tetraethoxysilane, solvent composition and coating method in Examples 7 to 8 are different. Please refer to Table 1 for its detailed composition.

Example 9

1.0 parts by weight of ethylene-vinyl alcohol copolymer (trade name 414077, purchased from U.S. Sigma-Aldrich company), is placed in 90 parts by weight of solvent to form a reaction solution, the solvent is an aqueous solution of isopropanol, isopropanol and Water is prepared according to the weight percentage of 60:40. Then, the reaction solution was heated to 95° C., reacted for 2 hours, and cooled to room temperature after forming a transparent and clear reaction solution. Then, 14.4 parts by weight of tetraethoxysilane and 3.6 parts by weight of 3-glycerolpropyltrimethoxysilane were added to the solution, and a mixed solution was formed after uniform stirring, and then 0.2 parts by weight of hydrochloric acid with a weight concentration of 37% was added The aqueous solution was hydrolyzed in the mixed solution for 1 hour to obtain a transparent and clear coating solution. Finally, the transparent and clear coating solution is applied to one surface of a polypropylene microporous membrane (trade name D120D, thickness is 20 μm, manufactured by Taiwan Mingji Materials Co., Ltd.) to form a composite coating, and then the porous membrane with a composite coating Drying is carried out, the drying temperature is 80° C., and the drying time is 3 minutes. Finally, a heat-resistant porous isolation membrane is prepared.

Comparative example 1

The porous separator used in Comparative Example 1 was a commercially available single-layer polypropylene microporous membrane with a thickness of 20 μm (trade name D120D, manufactured by BenQ Materials, Taiwan).

Comparative example 2

The porous isolation membrane used in Comparative Example 2 is a commercially available porous isolation membrane coated with ceramic particles (purchased from Shanghai Renyi Technology Co., Ltd.), and its substrate is a single-layer polypropylene microporous membrane with a thickness of 20 μm. It is aluminum oxide particles, and the coating thickness is 5 μm.

Comparative example 3

10 parts by weight of tetraethoxysilane were uniformly dissolved in 85 parts by weight of ethanol to form a reaction solution, and then 10 parts by weight of aqueous hydrochloric acid solution with a weight concentration of 1.8% was added to the reaction solution for hydrolysis reaction for 1 hour to obtain transparent and clear coating solution. Finally, the coating solution is applied to both surfaces of polypropylene microporous membrane (trade name D120D, thickness is 20 μm, manufactured by Taiwan Mingji Materials Co., Ltd.) to form a silicon dioxide coating, and then the The microporous membrane was dried at a drying temperature of 80° C. and a drying time of 3 minutes. Finally, a heat-resistant porous isolation membrane is prepared.

Comparative example 4

20 parts by weight of tetraethoxysilane were uniformly dissolved in 80 parts by weight of ethanol to form a reaction solution, and then 10 parts by weight of aqueous hydrochloric acid with a weight concentration of 1.8% was added to the reaction solution for hydrolysis for 1 hour to obtain a transparent and clear solution. coating solution. Finally, the coating solution is applied to both surfaces of polypropylene microporous membrane (trade name D120D, thickness is 20 μm, manufactured by Taiwan Mingji Materials Co., Ltd.) to form a silicon dioxide coating, and then the The microporous membrane was dried at a drying temperature of 80° C. and a drying time of 3 minutes. Finally, a heat-resistant porous isolation membrane is prepared.

Table 1: Detailed composition and characteristics of Examples 1-9

Table 2: Detailed composition and properties of Comparative Examples 1-4

From the properties shown in Table 1 to Table 2, the heat-resistant porous isolation films prepared in Examples 1 to 9 of the present invention all have good heat-resistant properties, and the shrinkage rate is about 10% to 21%. , while Comparative Example 1 is a single-layer polypropylene microporous separator, with a heat shrinkage rate of 31.9%, and poor heat resistance.

According to the surface energy test data, the surface energies of Examples 1 to 9 are almost greater than 50 dyne/cm ² , and they have good hydrophilicity, so they have good adsorption to the electrolyte. Comparative Example 1 is a polyolefin separator, which is a non-polar material, and its surface energy is 34 dyne/cm ² , which is relatively hydrophobic. The commercially available porous separator of Comparative Example 2 has alumina particles on its surface, has a surface energy of 36 dyne/cm ² , and is hydrophobic. The silicon dioxide-coated separators of Comparative Examples 3 to 4 have a surface energy of 34 dyne/cm ² , which is relatively hydrophobic because the surface energy is too small. Therefore, the separators shown in Comparative Example 1 to Comparative Example 4 have poor wetting effect on the electrolyte.

From the data of air permeability test, the gas permeability (Gurley) in Examples 1 to 9 is below 30sec/10c.c., preferably up to 14sec/10c.c.

Therefore, it can be seen from the above that the heat-resistant porous separator proposed by the present invention can have good heat resistance and electrolyte adsorption capacity at the same time.

To sum up, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the protection scope of the appended claims of the present invention.

Claims (13)

1. A heat-resistant porous separator applied to lithium-ion batteries, characterized in that, the heat-resistant porous separator comprises: Porous substrates; and The composite coating is disposed on at least one surface of the porous substrate, wherein the composite coating is an interpenetrating polymer network structure composed of a hydrophilic polymer and a silica polymer network structure. The silicon polymer network structure is formed by the silica precursor through hydrolysis and condensation reaction. 2. The heat-resistant porous isolation membrane as claimed in claim 1, characterized in that, the material of the porous substrate is high-density polyethylene, polypropylene, polyvinyl chloride, polyvinyl fluoride, polyester, polyamide or the like. combination. 3 . The heat-resistant porous isolation membrane of claim 1 , wherein the weight ratio of the hydrophilic polymer to the silica precursor is between 0.008 and 1.5. 4. The heat-resistant porous separator according to claim 1, wherein the hydrophilic polymer is ethylene-vinyl alcohol copolymer, polyvinyl alcohol or any combination of the above materials. 5. The heat-resistant porous isolation membrane according to claim 1, wherein the composite coating further comprises a dispersant. 6. The heat-resistant porous isolation membrane as claimed in claim 5, wherein the dispersant is 3-glycerolpropyltrimethoxysilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane , 3-(methacryloyloxy)propyltrimethoxysilane or any combination of the above materials. 7. A method for manufacturing a heat-resistant porous isolation membrane, characterized in that the method comprises: Provide a porous substrate; Adding 0.2 to 1.5 parts by weight of a hydrophilic polymer to 90 to 98 parts by weight of a solvent to form a reaction solution; Adding 1 to 25 parts by weight of a silicon dioxide precursor to the reaction solution to form a mixed solution; Adding aqueous hydrochloric acid to the mixed solution for hydrolysis and condensation reaction to form a transparent and clear solution; coating the transparent and clear solution on at least one surface of the porous substrate to form a composite coating; and drying the porous substrate with the composite coating to produce a heat-resistant porous isolation membrane. 8 . The method for manufacturing a heat-resistant porous separator according to claim 7 , wherein the hydrophilic polymer is ethylene-vinyl alcohol copolymer, polyvinyl alcohol or any combination of the above materials. 9. The method for manufacturing a heat-resistant porous isolation membrane according to claim 7, wherein the solvent is water, ethanol, isopropanol, methanol or any combination of the above materials. 10. The method for manufacturing a heat-resistant porous isolation membrane according to claim 7, wherein the silicon dioxide precursor is tetraethoxysilane, tetramethoxysilane, trimethoxysilane or any of the above-mentioned materials. combination. 11. The manufacture method of heat-resistant porous separator as claimed in claim 7, characterized in that, the material of the porous substrate is high density polyethylene, polypropylene, polyvinyl chloride, polyvinyl fluoride, polyester, poly Amides or any combination of the above materials. 12 . The method for manufacturing a heat-resistant porous separator according to claim 7 , further comprising adding a dispersant to the mixed solution before adding the hydrochloric acid aqueous solution to the mixed solution. 13 . 13. The manufacture method of heat-resistant porous isolation membrane as claimed in claim 12, it is characterized in that, the dispersant is 3-glycerol propyltrimethoxysilane, vinyltrimethoxysilane, 3-aminopropyl triethyl Oxysilane, 3-(methacryloxy)propyltrimethoxysilane, or any combination of the above materials.