TW202209744A - Seperator, metal ion battery using the same, and manufacturing method thereof - Google Patents

Abstract

A separator, a metal ion battery using the same, and a manufacturing method thereof are provided. The separator includes a porous base layer and a ceramic material. The porous base layer includes a plurality of fibers that are interwoven with one another, and the porous base layer is divided into an outer region and a core region. The ceramic material is formed on the surfaces of the fibers in the outer region and the core region by atomic layer deposition.

Description

Separator, metal ion battery using the same, and manufacturing method thereof

The present invention relates to a separator, a metal ion battery using the same, and a manufacturing method thereof, in particular to a ceramic separator, a metal ion battery using the same, and a manufacturing method.

Metal-ion batteries (eg, lithium-ion batteries) are currently widely used in electronic devices such as notebook computers, digital cameras, and mobile phones. Taking lithium-ion batteries as an example, lithium-ion batteries have the advantages of excellent energy density (High Energy Density), no memory effect (No Memory Effect), long cycle life (Long Cycle Life) and low self-discharge (Low Self-discharging) and other advantages , and has the potential to be applied to electric vehicles or smart grids.

Existing metal ion batteries at least include a positive electrode, a negative electrode, an electrolyte and a separator. The separator is placed between the positive electrode and the negative electrode to avoid contact between the positive and negative electrodes and to ensure that metal ions can be transferred there. Although the separator does not participate in the electrochemical reaction, the structure and properties of the separator can affect the performance of metal-ion batteries, such as cycle life, safety, energy density, power density, and battery thickness.

Further, the separator has a plurality of pores to absorb the electrolyte, and the metal ions are transported in the pores filled with the electrolyte in the separator. Therefore, the wettability (Wettability) of the electrolyte to the separator will affect the internal resistance (Internal Resistance) and ionic conductivity (Ionic Conductivity), and the wettability of the separator depends on the properties, porosity and pore size of the selected material. .

On the other hand, existing separators include layers of polymeric materials having microporosity. Although the polymer material layer can provide sufficient mechanical strength and chemical stability at normal temperature, it may have greater thermal shrinkage at high temperature. In addition, when the temperature exceeds the melting temperature of the polymer material layer, the separator will be dissolved, resulting in a short circuit between the positive and negative electrodes, and may even cause safety problems such as battery combustion or explosion. Therefore, in the prior art, a ceramic coating is formed on the polymer material layer to improve the thermal stability of the existing separator.

However, forming a ceramic coating on the polymer material layer increases the overall thickness of the separator and may have problems with powder falling. Therefore, how to improve the heat resistance of the existing separator without increasing the thickness is still one of the important issues to be solved by this business.

The technical problem to be solved by the present invention is to provide a separator, a metal ion battery using the same and a manufacturing method thereof in view of the deficiencies of the prior art, so as to improve the thermal stability and wettability of the separator without increasing the thickness of the separator. sex.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a separator for metal ion batteries, which includes a porous base layer and a ceramic material. The porous base layer includes a plurality of fibers interwoven with each other, and the porous base layer is divided into an outer region and a middle region. The ceramic material is distributed in the outer and middle regions of the porous base layer, and is deposited on the surface of the plurality of fibers.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a metal ion battery, which includes a positive electrode, a negative electrode and the aforementioned separator, and the separator is located between the positive electrode and the negative electrode.

In order to solve the above-mentioned technical problem, another technical solution adopted by the present invention is to provide a method for manufacturing a separator for a metal ion battery, which includes: providing a porous base layer with a plurality of interwoven fibers, wherein , the porous base layer is divided into an outer area and a middle area; and a ceramization process is performed on the porous base layer by an atomic layer deposition process, so that a ceramic material is distributed in the outer area and the middle area of the porous base layer, and deposited on the surface of multiple fibers.

One of the beneficial effects of the present invention is that the separator provided by the present invention, the metal ion battery using the same and the manufacturing method thereof, can be distributed in the outer and middle regions of the porous base layer through "ceramic materials, and deposited on multiple "The surface of the strip fiber" and the technical scheme of "using an atomic layer deposition process to perform a ceramic treatment on the porous base layer", so that the isolation film has better thermal stability and wettability without increasing the thickness of the isolation film. .

For a further understanding of the features and technical content of the present invention, please refer to the following detailed descriptions and drawings of the present invention. However, the drawings provided are only for reference and description, and are not intended to limit the present invention.

The following is a description of the embodiments of the “separator film, metal ion battery using the same and its manufacturing method” disclosed in the present invention through specific specific examples. Those skilled in the art can understand the advantages of the present invention from the content disclosed in this specification. with effect. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are merely schematic illustrations, and are not drawn according to the actual size, and are stated in advance. The following embodiments will further describe the related technical contents of the present invention in detail, but the disclosed contents are not intended to limit the protection scope of the present invention. In addition, the term "or", as used herein, should include any one or a combination of more of the associated listed items, as the case may be.

Referring to FIG. 1 and FIG. 2 , FIG. 1 is a partial schematic diagram of an isolation film according to an embodiment of the present invention. FIG. 2 is an enlarged schematic view of part II of FIG. 1 . The separator 1 of this embodiment is applied in a metal ion battery to avoid contact between the positive and negative electrodes, and is used to conduct metal ions. According to the requirements of different metal ion batteries, the separator 1 will have different thicknesses. In one embodiment, the total thickness of the isolation film 1 is between 6 μm and 25 μm.

As shown in FIGS. 1 and 2 , the separator 1 includes a porous base layer 10 and a ceramic material 11 . The porous base layer 10 has a plurality of micropores h1 and a plurality of fibers 100 interwoven with each other.

The porous base layer 10 may be a single-layer structure, and the material of the porous base layer 10 may be selected from at least one selected from the group consisting of polyethylene, polypropylene, polyacrylonitrile, polyethylene oxide, glass fiber, and any combination thereof. One, the present invention is not limited. In another embodiment, the porous base layer 10 may also have a laminated structure. In detail, the porous base layer 10 may be a laminated structure of polyethylene (PP) layer/polypropylene (PE) layer/polyethylene (PP) or a laminated structure of polyethylene oxide (PEO) and polypropylene (PE). structure. That is, the material of the porous base layer 10 can also be selected differently according to the type of metal ion battery to which the separator 1 is applied.

In general, the porous base layer 10 can be divided into an outer region PR and a middle region CR. The plurality of fibers 100 located in the outer region PR are closer to the outer surfaces S1 and S2 of the porous base layer 10 , while the plurality of fibers 100 located in the middle region CR are in the core region of the porous base layer 10 .

Please also refer to FIG. 2 , the ceramic material 11 is not only distributed in the outer region PR of the porous base layer 10 , but also distributed in the middle region CR. That is, the ceramic material 11 is not only formed on the outer surfaces S1 and S2 of the porous base layer 10 , but will enter the inside of the porous base layer 10 and be deposited on the fibers 100 inside the porous base layer 10 . Besides, the ceramic material 11 is not doped in the fibers 100 , but is deposited on the surfaces 100 s of the plurality of fibers 100 .

In one embodiment, the ceramic material 11 is an atomic layer deposition ceramic layer. That is, the ceramic material 11 is formed on the plurality of fibers 100 of the porous base layer 10 through an atomic layer deposition process. Accordingly, each fiber 100 and the ceramic material 11 deposited thereon together form a composite fiber structure. The inner core of the composite fiber structure is a (polymer) fiber 100, and the outer covering layer is an atomic layer deposited ceramic layer. In one embodiment, the thickness of the ALD ceramic layer is from 1 nm to 3 nm. The present invention does not limit the type of the ceramic material 11 as long as it can be formed by an atomic layer deposition process and the isolation film 1 has better thermal stability. For example, the ceramic material 11 may be an oxide such as titanium oxide, aluminum oxide, silicon oxide, zinc oxide, tin oxide, zirconium oxide, or any combination thereof.

That is, the separator 1 of the embodiment of the present invention is a ceramic separator. However, unlike the prior art, the ceramic material 11 is not directly coated on the outer surfaces S1 , S2 of the porous base layer 10 , but is formed inside the porous base layer 10 . Therefore, the isolation film 1 of the embodiment of the present invention does not increase its overall thickness due to the ceramic material 11 .

It can be understood that, in this embodiment, since the ceramic material 11 can be formed inside the porous base layer 10 by an atomic layer deposition process, the ceramic material 11 may not necessarily be formed on every fiber 100 of the porous base layer 10 . In addition, when the fiber 100 is covered with the ceramic material 11, the ceramic material 11 may cover only a part of the surface 100s of the fiber 100, but not completely cover the entire surface 100s of the fiber 100.

Please refer to FIG. 3 , which is a partially enlarged schematic view of an isolation film according to another embodiment of the present invention. In the embodiment of FIG. 3 , the porous base layer 10 is subjected to surface modification treatment before the ceramicization treatment, for example, applying an oxygen plasma or an oxygen/argon mixed plasma to the porous base layer 10 or in the The porous base layer 10 is irradiated with ultraviolet light in an ozone atmosphere. Therefore, the surface roughness of the fibers 100 closer to the outer surfaces S1, S2 of the porous base layer 10 is greater than the surface roughness of the fibers 100 farther from the outer surfaces S1, S2. That is to say, in this embodiment, compared with the fibers 100 located in the middle region CR, the fibers 100 located in the outer region PR will have a relatively uneven modified surface 100s', but this is not the case in the present invention limit.

Please refer to FIG. 4 , which shows a scanning electron microscope (SEM) photograph of the isolation film according to one embodiment of the present invention, and its magnification is 50,000 times. In the separator shown in FIG. 4 , the porous base layer 10 is subjected to surface modification treatment before the ceramic material 11 is formed. After surface modification treatment (such as plasma treatment) and ceramicization treatment by ALD, after the ceramic material 11 is formed on the surface of the fiber 100, the microstructure of the surface of the separator will change slightly, but its overall thickness will not increase, and still retain the original void structure.

The present invention further provides a method for manufacturing a separator. Please refer to FIG. 5 , which is a flowchart of a method for fabricating an isolation film according to an embodiment of the present invention. In step S100, a porous base layer is provided, which has a plurality of fibers interwoven with each other, and the porous base layer is divided into an outer area and a middle area.

As mentioned above, the material of the porous base layer 10 can be selected from at least one of the group consisting of polyethylene, polypropylene, polyacrylonitrile, polyethylene oxide, glass fiber and any combination thereof. limit. It should be noted that, before the ceramic material 11 is formed, the porosity of the porous base layer 10 is about 35% to 48%, and the thickness of the porous base layer 10 is about 6 μm to 25 μm.

In addition, the porous base layer 10 can be divided into an outer region PR and a middle region CR closer to the outer surfaces S1, S2 (including the upper surface S1 and the lower surface S2 of the porous base layer 10). Accordingly, relative to the plurality of fibers 100 in the middle region CR, the positions of the plurality of fibers 100 in the outer region PR are closer to the outer surfaces S1 and S2 of the porous base layer 10, while the positions of the plurality of fibers in the middle region CR are closer to the outer surfaces S1 and S2 of the porous base layer 10 The location of 100 is in the core region of the porous base layer 10 .

In step S110, a surface modification treatment is performed on the porous base layer. After the step of performing the surface modification treatment, oxygen-containing functional groups may be formed on the surfaces 100s of the plurality of fibers 100 , so that the ceramic material 11 can be more easily formed on the surfaces 100s of the fibers 100 in subsequent steps. The aforementioned oxygen-containing functional group includes at least one of a hydroxyl group (-COH), a carboxyl group (-COOH) and a carbonyl group (-C=O).

In detail, in one embodiment, in the step of performing the surface modification treatment, an oxygen plasma or an oxygen/argon mixed plasma may be applied to the porous base layer 10 . In another embodiment, the porous base layer 10 is irradiated with ultraviolet light in an ozone atmosphere to form oxygen-containing functional groups on the surfaces 100s of the plurality of fibers 100 .

It should be noted that when an oxygen plasma or an oxygen/argon mixed plasma is applied to the porous base layer 10 , or ultraviolet light is irradiated to the porous base layer 10 , the plasma or the ultraviolet light will damage the porous base layer 10 . Lateral area PR. Therefore, the surface roughness of the fibers 100 closer to the outer surfaces S1, S2 of the porous substrate layer 10 is greater than the surface roughness of the fibers 100 farther from the outer surfaces S1, S2 of the porous substrate layer 10.

In other words, compared to the fibers 100 located in the core region, the fibers 100 closer to the outer surfaces S1 and S2 of the porous base layer 10 will have larger surface roughness. In addition, the fibers 100 closer to the outer surfaces S1, S2 of the porous base layer 10 may have uneven modified surfaces 100s'. However, after the surface modification treatment, oxygen-containing functional groups may be formed on the fibers 100 either in the outer region PR or the middle region CR.

Besides, by performing a surface modification treatment on the porous base layer 10 , the pore diameter of the micropores h1 located in the outer region PR of the porous base layer 10 can also be enlarged. In this way, when the ceramic material 11 is subsequently formed by the atomic layer deposition process, the ceramic material 11 is not only formed on the fibers 100 in the outer region PR, but also easily formed on the fibers 100 in the middle region CR.

When the porous base layer 10 is polyethylene, polypropylene, polyacrylonitrile or any combination thereof, the ceramic material 11 can be more easily formed on the fibers 100 by performing step S110. For example, when the porous base layer 10 has a laminated structure of polyethylene (PP) and polypropylene (PE), or when the material of the porous base layer 10 is polyethylene or polyacrylonitrile, surface modification can be performed. processing to form oxygen-containing functional groups on the fiber 100 .

Accordingly, after the surface modification treatment of the porous base layer 10 is performed, the ceramic material 11 can be more easily deposited on the fibers 100 in the subsequent atomic layer deposition process, thereby increasing the deposition rate of the ceramic material 11 . In this way, more ceramic material 11 can be deposited in the porous base layer 10 in a relatively short period of time.

However, as shown in FIG. 5 , in another embodiment, the manufacturing method may directly execute step S120 while omitting step S110 . For example, when the porous base layer 10 has a laminated structure of polyethylene oxide (PEO) and polypropylene (PE), or when the material of the porous base layer 10 is glass fiber, after step S110 is performed, the Step S120.

In step S120, an atomic layer deposition process is used to perform a ceramization process on the porous base layer, so that a ceramic material is distributed in the outer and middle regions of the porous base layer and deposited on the surfaces of the plurality of fibers. After step S120 is performed, the isolation film 1 shown in FIG. 1 and FIG. 2 can be formed. In one embodiment, the ceramic material 11 may be formed within the porous base layer 10 using a continuous (roll-to-roll) atomic layer deposition apparatus.

In detail, in the atomic layer deposition process, the porous base layer 10 is disposed in the reaction chamber, and different precursor gases are sequentially introduced into the reaction chamber to deposit the porous base layer 10 in the reaction chamber. The ceramic material 11 is formed.

The type of the precursor gas can be determined according to the ceramic material 11 to be formed, and is not limited in the present invention. A continuous self-limiting reaction occurs between the precursor gas and the surface of the fibers 100 , thereby forming a ceramic material on the fibers 100 inside the porous substrate layer 10 . It is worth mentioning that the aforementioned precursor gas can enter the intermediate region CR of the porous base layer 10 through the micropores h1 of the porous base layer 10, so that the ceramic material 11 is formed on the surface 100s of the fibers 100 in the intermediate region CR. .

Since the ceramic material 11 is not stacked on the outer surfaces S1, S2 of the porous base layer 10, but is formed on the fibers 100 inside the porous base layer 10, the thickness of the separator 1 of the embodiment of the present invention will not be greatly increased , which is similar to the thickness of the porous base layer 10 before the ceramization treatment. In one embodiment, the difference between the thickness of the porous base layer 10 before the ceramization process (step S120 ) and the thickness of the separator 1 after the ceramization process is performed is less than 0.5%.

In addition, the thickness of the separator 1 may range from 6 μm to 25 μm according to the metal ion battery to which the separator 1 is to be applied. In one embodiment, when the separator 1 is used in a lithium ion battery, the thickness of the separator 1 is about 6 μm to 12 μm.

In addition, in the embodiment of the present invention, using the atomic layer deposition process to form the ceramic material 11 in the porous base layer 10 can improve the wettability and thermal stability of the isolation film 1, but does not greatly reduce the pores of the isolation film 1 Rate. That is to say, the isolation film 1 manufactured by the method of the embodiment of the present invention can improve the wettability and thermal stability of the isolation film 1 without excessively sacrificing the porosity.

In one embodiment, after step S120 is performed, the porosity of the isolation film 1 is only reduced by at most 0.04% compared to the porosity of the untreated porous base layer 10 , but the thermal stability and wettability of the isolation film 1 are reduced by at most 0.04%. Sex has been significantly improved.

Referring to FIG. 6 , a partial schematic diagram of a metal ion battery according to an embodiment of the present invention is shown. The metal ion battery Z1 may be one of a lithium ion battery, a magnesium ion battery, an aluminum ion battery, a lithium sulfur battery or a sodium ion battery, which is not limited in the present invention.

The metal-ion battery Z1 at least includes a casing Z10 , a positive electrode Z11 , a negative electrode Z12 and a separator Z13 . The positive electrode Z11 , the negative electrode Z12 and the separator Z13 are all disposed in the casing Z10 , and the separator Z13 is located between the positive electrode Z11 and the negative electrode Z12 to avoid contact between the positive electrode Z11 and the negative electrode Z12 . The isolation film Z13 can be the isolation film 1 shown in FIG. 2 or FIG. 3 , and can be manufactured by the manufacturing method shown in FIG. 5 , which is not repeated here. In addition, the metal ion battery Z1 also includes an electrolyte (not shown) in the casing Z10, and the positive electrode Z11, the negative electrode Z12 and the separator Z13 are all in contact with the electrolyte.

The present invention also provides experimental data, which proves that the separator of the embodiment of the present invention has better thermal stability, and can be applied to metal ion batteries. Please refer to FIG. 7 , which shows the thermal stability of the isolation films of different embodiments of the present invention and the isolation films of the comparative example.

It should be noted that, in FIG. 7 , the material of the separator of the comparative example is polypropylene, while in the separators of Examples 1 to 3, the material of the porous base layer 10 is also polypropylene, and the material of the ceramic material 11 is all polypropylene. is titanium oxide. In other words, the separator of the comparative example is a porous base layer that has not been ceramized. The structures of the isolation films of the first to third embodiments may refer to FIGS. 1 to 2 . In addition, the separators of Examples 1 to 3 are all subjected to surface modification treatment before the ceramicization treatment.

In FIG. 7 , the curve 7A corresponds to the vertical axis on the right side, that is, the maximum cracking temperature measured by the comparative example and the examples 1 to 3 respectively. In addition, the curve 7B corresponds to the left vertical axis, that is, the ratio between titanium (Ti) atoms and carbon atoms in Comparative Examples and Examples 1 to 3.

The difference between the first embodiment and the third embodiment is the amount of the ceramic material 11 . In one embodiment, X-ray photoelectron spectroscopy (XPS) can be used to analyze the ratio between titanium (Ti) atoms and carbon atoms to define the content of the ceramic material 11 .

As shown in FIG. 7 , the content of titanium atoms in Example 1 is the lowest, while the content of titanium atoms in Example 3 is the highest, and the content of titanium atoms in Example 2 is between Example 1 and Example 2. In detail, the ratios of titanium/carbon atoms in Examples 1 to 3 are about 0.68 at.%, 1.35 at.% and 6.93 at.%, respectively.

In addition, it can be seen from FIG. 7 that, compared with the comparative example, Examples 1 to 3, that is, the isolation membranes after ceramization treatment, all have higher maximum cracking temperatures. The maximum cracking temperature of Comparative Examples and Examples 1 to 3 was measured by thermogravimetric analysis (TGA, Perkin Elmer TA7). Thermogravimetric analysis was performed by heating from 30 ^° C to 700 ^° C at a heating rate of 10 ^° C per minute. In detail, the maximum cracking temperature of the isolation membrane of the comparative example is about 397 ^° C, while the maximum cracking temperatures of Examples 1 to 3 are 415 ^° C, 425 ^° C and 450 ^° C, respectively. Accordingly, the isolation film 1 of the embodiment of the present invention does have better thermal stability. Further, as the content of the ceramic material 11 in the separator 1 is higher, the thermal stability is also better.

Please refer to Table 1 below, which shows the area retention rate, contact angle and porosity of Comparative Examples and Examples 1 to 3. When measuring the area maintenance ratio, the comparative example and the first to third examples were baked at a temperature of 130 ^° C. for one hour, and the area difference before and after the baking was measured.

In the present invention, the contact angle of the electrolyte to the comparative example and the first to third examples is measured by the sessile drop method to compare the wettability (Wettability) of the comparative example and the first to third examples. The electrolyte used for the measurement is lithium hexafluorophosphate (LiPF6) with a concentration of 1.0M in propylene carbonate (PC)/diethyl carbonate (DEC)/ethyl methyl carbonate (ethyl methyl carbonate) , EMC) mixture.

The ionic conductivity of Comparative Examples and Examples 1 to 3 was analyzed by electrochemical impedance spectroscopy (EIS) in the frequency band of 0.01 Hz to 100 kHz. The discharge capacity was measured under the condition of a discharge rate of 0.2C for the metal ion batteries using the separators of Comparative Examples and Examples 1 to 3, respectively.

Table 1 Comparative example Example 1 Embodiment 2 Embodiment 3 Area maintenance rate (%) 80.5 90.8 91.4 91.8 Contact angle (degrees) 44 34.5 18.1 15.2 Porosity(%) 38 38.2 38.1 37.6 Ionic conductivity (mS/cm) 0.086 0.097 0.098 0.108 Battery internal resistance (Ω) 0.235 0.218 0.217 0.205 Discharge capacity (mAh) 365 376 397 410

Referring to Table 1, the area retention rate of the comparative example is 80.5%, while the area retention rates of Examples 1 to 3 are 90.8%, 91.4% and 91.8%, respectively. That is, as the content of ceramic material in the separator is higher, the thermal shrinkage rate is lower. In addition, compared with the comparative example, the contact angles of Examples 1 to 3 are greatly reduced. Therefore, the first to third embodiments have better hydrophilicity, and can absorb the molecules of the electrolyte, thereby increasing the wettability.

It is worth mentioning that the formation of the ceramic material 11 in the porous base layer 10 by the atomic layer deposition process does not greatly reduce the porosity of the isolation membrane 1 . That is, although the ceramic material 11 is formed in the porous base layer 10, the ceramic material 11 does not block the passage of ion transfer. Therefore, the ionic conductivity of Examples 1 to 3 is even better than that of the comparative example.

In addition, referring to Table 1, compared with the metal ion battery applying the separator of the comparative example, the metal ion battery applying the separator of Examples 1 to 3 has significantly lower battery internal resistance and higher discharge capacity.

Please refer to FIG. 8 , which shows the charge-discharge cycle life of the metal-ion battery using the separators of Example 3 and Comparative Example respectively at 55 ^° C. The curve 8A and the curve 8B respectively represent the discharge capacity of the third embodiment and the comparative example when they are charged and discharged for 100 times at a charge-discharge rate of 1C. It can be seen from FIG. 8 that after 100 times of charge and discharge, the discharge capacity of the metal ion battery applying the comparative example is reduced by about 12.9%. In contrast, the discharge capacity of the metal-ion battery of Application Example 3 is only reduced by about 8.7%. In addition, after 100 times of charging and discharging, the stable coulombic efficiencies of Example 3 and Comparative Example are still maintained above 99%.

[Advantageous effects of the embodiment]

One of the beneficial effects of the present invention is that the separator provided by the present invention, the metal ion battery using the same, and the manufacturing method thereof, can be distributed in the outer region PR and the middle region CR of the porous base layer 10 through "the ceramic material 11, and deposited on the surface 100s of the plurality of fibers 100 ” and the technical solutions of “using an atomic layer deposition process to perform a ceramic treatment on the porous base layer 10”, so that the isolation film 1 has a thickness without increasing the thickness of the isolation film 1. Better thermal stability and wettability.

In addition, using the atomic layer deposition process to form the ceramic material 11 in the porous base layer 10 does not greatly reduce the porosity of the separator 1 and does not affect the application of the separator 1 in the metal ion battery Z1 . After practical tests, the ceramized separator 1 even has better ionic conductivity.

Before performing the ceramization process, a surface modification process is performed on the porous base layer 10 . Accordingly, in the atomic layer deposition process, the ceramic material 11 can be more easily deposited on the fibers 100 , thereby increasing the deposition rate of the ceramic material 11 . In this way, more ceramic material 11 can be deposited in the porous base layer 10 in a relatively short period of time.

The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, any equivalent technical changes made by using the contents of the description and drawings of the present invention are included in the application of the present invention. within the scope of the patent.

1: Isolation film 10: Porous base layer PR: lateral region CR: middle zone S1, S2: outer surface h1: Micropore 100 fibers 100s, 100s’: Surface 11: Ceramic materials Z1: Metal-ion battery Z10: Shell Z11: positive electrode Z12: negative pole Z13: Isolation film 7A, 7B, 8A, 8B: Curve

FIG. 1 is a partial schematic diagram of an isolation film according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic view of part II of FIG. 1 .

FIG. 3 is a partial enlarged schematic view of an isolation film according to another embodiment of the present invention.

4 is a scanning electron microscope photograph of a separator according to an embodiment of the present invention.

FIG. 5 is a flowchart of a method for fabricating an isolation film according to an embodiment of the present invention.

6 is a schematic partial cross-sectional view of a metal ion battery according to an embodiment of the present invention.

FIG. 7 shows the thermal stability of the isolation films of the examples and comparative examples of the present invention.

FIG. 8 shows the cycle life of the metal-ion battery using the separators of Example 3 and Comparative Example at 55 ^o C, respectively.

10: Porous base layer

PR: lateral region

CR: middle zone

h1: Micropore

100: Fiber

100s: Surface

11: Ceramic materials

Claims (16)

A separator for a metal ion battery, comprising: a porous base layer comprising a plurality of interwoven fibers, wherein the porous base layer is divided into an outer region and an intermediate region; and A ceramic material is distributed in the outer region and the middle region of the porous base layer, and is deposited on the surface of a plurality of the fibers. The isolation film of claim 1, wherein the ceramic material is at least one selected from the group consisting of titanium oxide, aluminum oxide, silicon oxide, zinc oxide, tin oxide, zirconium oxide, and any combination thereof . The isolation film of claim 1, wherein the ceramic material is an atomic layer deposition ceramic layer, and the thickness of the atomic layer deposition ceramic layer is from 1 nm to 3 nm. The separator according to claim 1, wherein the ceramic material is oxide, and the material of the porous base layer is selected from polyethylene, polypropylene, polyacrylonitrile, polyethylene oxide, glass fiber and any Combining at least one of the group consisting of. The isolation film of claim 1, wherein the total thickness of the isolation film is between 6 μm and 25 μm. The separator of claim 1, having a maximum cracking temperature measured by thermogravimetric analysis of at least 400 ^° C. The separator of claim 1, wherein the fibers closer to the outer surface of the porous base layer have a surface roughness greater than that of the fibers further away from the outer surface of the porous base layer Surface roughness. A metal-ion battery comprising: a positive electrode; a negative electrode; and The separator according to any one of claims 1 to 7, which is provided between the positive electrode and the negative electrode. The metal-ion battery according to claim 8, wherein the metal-ion battery is a lithium-ion battery, a magnesium-ion battery, an aluminum-ion battery, a lithium-sulfur battery or a sodium-ion battery. A manufacturing method of a separator for a metal ion battery: providing a porous base layer having a plurality of interwoven fibers, wherein the porous base layer is divided into an outer region and an intermediate region; and A ceramization treatment is performed on the porous base layer by an atomic layer deposition process, so that a ceramic material is distributed in the outer region and the middle region of the porous base layer, and deposited on the surfaces of the plurality of fibers . The manufacturing method of claim 10, wherein a surface modification treatment is performed on the porous base layer before the ceramization treatment is performed. The manufacturing method according to claim 11, wherein, in the step of performing the surface modification treatment, an oxygen plasma or an oxygen/argon mixed plasma is applied to the porous base layer, so that a plurality of the The surface of the fiber forms oxygen-containing functional groups. The manufacturing method of claim 11, wherein, in the step of performing the surface modification treatment, the porous base layer is irradiated with ultraviolet light under an ozone atmosphere to form a surface containing a plurality of the fibers. oxygen functional group. The production method according to claim 12 or 13, wherein the oxygen-containing functional group includes at least one of a hydroxyl group (-COH), a carboxyl group (-COOH), and a carbonyl group (-C=O). The manufacturing method of claim 11, wherein the fibers closer to the outer surface of the porous base layer have a surface roughness greater than that of the fibers further away from the outer surface of the porous base layer Surface roughness. The manufacturing method of claim 11, wherein the material of the porous base layer is selected from the group consisting of polyethylene, polypropylene, polyacrylonitrile, polyethylene oxide, glass fiber and any combination thereof at least one.

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