KR20170037495A - Composite membrane, preparing method thereof, anode structure including the composite membrane, and lithium secondary battery including the anode structure - Google Patents

Abstract

The present invention relates to a composite membrane, a production method thereof, a negative electrode structure comprising the same, and a lithium secondary battery comprising the negative electrode structure. The composite membrane comprises: an organic film having a plurality of through holes; and a plurality of ion conductive inorganic particles disposed in the through holes, wherein a contact angle of the composite membrane or the plurality of ion conductive inorganic particles is 30 to 90 degrees.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite membrane, a method of manufacturing the same, a cathode structure including the same, and a lithium secondary battery including the composite membrane, the preparing method thereof, the anode structure including the composite membrane,

And a lithium secondary battery including the negative electrode structure.

The lithium air battery includes a cathode including a redox catalyst of oxygen using a cathode capable of intercalating / deintercalating lithium ions and oxygen in the air as a cathode active material, and a lithium ion conductive medium is provided between the anode and the cathode.

The theoretical energy density of lithium air cells is over 3000Wh / kg, which is much higher than that of lithium ion batteries. In addition, lithium air cells are environmentally friendly and have better safety than lithium-ion batteries. In order to improve the cell performance of such a lithium air battery, a separation membrane having an excellent function of shutting off moisture and gas and having an excellent function of passing lithium ions is required.

One aspect is to provide a novel composite membrane and a method for producing the same.

Another aspect is to provide a negative electrode structure employing the composite membrane.

Another aspect is to provide a lithium secondary battery improved in cell performance by employing the above-described cathode structure.

On one side

There is provided a composite film comprising an organic film having a plurality of through holes and ion conductive inorganic particles disposed in the through holes, wherein the composite film or the plurality of ion conductive inorganic particles have a contact angle of 30 to 90 °.

According to other aspects

A first step of watering an ion conductive inorganic particle on at least one surface with a mixture comprising a polymerizable water-insoluble floating compound and a solvent;

A second step of stirring the resultant;

A third step of removing the solvent from the resultant product; And

And a fourth step of carrying out a polymerization reaction to produce a composite membrane as described above.

A hydrophobic coating film may be formed on at least one surface of the plurality of ion conductive inorganic particles. A hydrophobic coating film may be formed on one surface of the plurality of ion conductive inorganic particles that are not exposed on the surface of the composite membrane.

According to another aspect, there is provided a cathode structure comprising a cathode, an electrolyte, and a composite membrane as described above.

According to another aspect, there is provided a lithium secondary battery including the above-described cathode structure.

The lithium secondary battery is a lithium air battery.

According to one aspect, there is provided a composite membrane which is superior in gas and moisture barrier properties, has improved ionic conductivity, and can be made lighter and thinner. By using the composite membrane, a lithium secondary battery improved in capacity and life can be manufactured.

IA is a schematic perspective view of a composite membrane according to one embodiment.
FIG. 1B is a view for explaining the movement of lithium ions and the blocking of oxygen in the composite membrane according to one embodiment. FIG.
Fig. 2 shows a cross section of the composite membrane shown in Fig.
3A shows a structure of a negative electrode structure employing a composite membrane according to another embodiment.
FIG. 3B schematically shows a structure of a lithium air cell employing a composite membrane according to another embodiment.
3C is a schematic view illustrating a structure of a lithium secondary battery according to another embodiment.
Figure 4 is intended to illustrate the structure of a composite membrane according to one embodiment.
5 is intended to illustrate the process of making a composite membrane according to one embodiment.
6A to 6C show definitions of contact angles.
6D is a phase diagram of a composite membrane according to one embodiment.
FIGS. 7A to 7C are optical microscope photographs of composite membranes prepared according to Example 3. FIG.
8A shows impedance characteristics of a lithium symmetric cell employing a composite membrane manufactured according to Example 3. FIG.
Figure 8b shows the conductivity of the composite membrane according to one embodiment.
FIG. 8C shows the change in specific resistance of the composite film according to an embodiment according to temperature.
FIG. 8D shows the definition of the area fraction (Xp) of LTAP particles and the thickness (tp) of ion conductive inorganic particles in the composite membrane of FIG. 8B.
9 shows changes in oxygen permeability using the composite membrane of Example 3 and the membrane of Comparative Example 1-2.
FIG. 10 shows the charge-discharge characteristics of a lithium air cell produced according to Example 4. FIG.
11 shows the cycle characteristics of a lithium air battery manufactured according to Example 4. Fig.
12A and 12B are graphs showing the crystal phase of a lithium-titanium-aluminum-molybdenum composite in which a hydrophobic coating film modified with isobutyl (triethoxy) silane (IB) and (3-methacrylpropyltrimethoxysilane (PM) X-ray photoelectron spectroscopy (XPS) analysis of phosphate (LTAP) particles is shown.

Hereinafter, a composite membrane according to one embodiment, a method for manufacturing the same, a lithium air battery and a lithium secondary battery employing the composite membrane will be described in detail.

An organic film having a plurality of through holes and a plurality of ion conductive inorganic particles disposed in the through holes, wherein the composite film or the plurality of ion conductive inorganic particles has a contact angle of 30 to 90 ° do.

A hydrophobic coating film may be formed on at least one surface of the plurality of ion conductive inorganic particles. A hydrophobic coating film may be formed on one surface of the plurality of ion conductive inorganic particles that are not exposed on the surface of the composite membrane.

In the composite membrane according to an embodiment, the contact angle formed by the plurality of ion conductive inorganic particles having the hydrophobic coating film disposed thereon and the organic film at the interface between the organic film and the air (and water) may be 30 to 90 °.

The contact angle has a range of, for example, 40 to 85 degrees.

The contact angle is closely related to the detailed structure of the composite membrane. The detailed structure of the composite membrane refers, for example, to the arrangement of ion conductive inorganic particles in the organic film, the presence or absence of pin holes, and the like.

In the present specification, the " contact angle " can be explained by the interfacial tension between the organic film and the ion conductive inorganic particle and the fluid present on the organic film. Here, the organic film exhibits the same interfacial tension as the organic film forming material, for example, a layer made of a polymerizable water-insoluble floating compound (or polymerizable monomer). Therefore, the interfacial tension between the organic film and the ion conductive inorganic particles and the fluid present on the organic film can be controlled by controlling the interfacial tension between the polymerizable non-aqueous floating compound (or polymerizable monomer) (hereinafter referred to as " monomer "), is the same as the ion conductivity (hereinafter referred to as "particles"), inorganic particles and a fluid (fluid) the interfacial tension (γ _ap, γ _wp, γ _mp) of. The fluid represents air or water. And a, p, w, and m represent air, particle, water, and monomer layers, respectively.

6A and 6B are views for explaining the contact angle. Referring to this, the contact angle will be described in more detail.

The interfacial tension at the fluid / particle interface can be explained by the fluid / fluid interfacial tension and the contact angle by the Young's equation of the following formulas (1) to (3).

[Formula 1]

γ _ap - ? _wp =? _aw cosθ _awp

[Formula 2]

? _ap -? _mp =? _am cosθ _amp

[Formula 3]

γ _wp - gamma _mp = gamma _wm cosθ _wmp

6A, when the particles 600 are dispersed in the monomer layer 620, the particles 600 are attached at the interface between the air 630, which is a fluid, and the monomer layer 620, which is a fluid. As shown in FIG. 6B, when the particles 600 are dispersed in the monomer layer 620 disposed on the surface of the water 610, the particles 600 adhere to the fluid / fluid interface. According to Figure 6c, the particles 600 are attached to the interface of the air 630 with the water 610, which is the fluid / fluid interface. As a result, the particles 600 form a thermodynamically stable structure in the A-E phase of FIG. 6D.

FIG. 6D shows a phase diagram for classifying the structure of a composite membrane, assuming that ion conductive inorganic particles such as LTAP are similar to spheres having a certain diameter.

If the A-E phase is thermodynamically favorable, the total interfacial energy of the particles when the particles 600 adhere to the fluid / fluid interface under an air atmosphere is represented by the following formulas 4 to 8. At this time, assuming that the thickness of the monomer layer is smaller than the thickness of the particles, the particle 600 adheres only to the monomer layer 620 existing on the surface of the water 610 on the surface A 610.

[Formula 4]

ΔE _A = - 4πR ² γ _am cos θ _amp

Particles (600) on B are attached only to water (610).

[Formula 5]

? E _B = - p? ² ? _Aw (1 + cos? _Awp ) ²

At C, the monomer of the monomer layer 620 is wetted at the surface of the water 610 and the particles 600 are attached to the interface of the air / monomer rather than the monomer / water.

[Formula 6]

? E _C = - AS _eq -? R ² ? _Aw (1 + cos? _Awp ) ²

At D, the monomer of the monomer layer 620 is wetted to the surface of the water 610 and the particles 600 are attached to the interface of the monomer / water, not the air / monomer.

[Equation 7]

_{△ E D = - AS eq -π} R 2 γ wm (1 + cosθ wmp) 2 - 4π R 2 γ aw cosθ awp

At E, the monomer of the monomer layer 620 is wetted to the surface of the water 610 and the particles 600 are attached to both the air / monomer and the monomer / water interface.

[Equation 8]

_{△ E E = - 0.5A S eq} - 0.5π R 2 γ am (1 + cosθ amp) 2 -0.5π R 2 γ wo (1 + cosθ wop)

_{^{- 0.5πR 2 γ wm (1 +}} cosθ wmp) 2 - 2π 2 γ aw cosθ awp

[Equation 9]

ΔE = - A S _eq = γ _m - γ _mw -? _aw

In the formula 6 to 9, S _eq, and A denotes an equilibrium host spreading factor (equibrium spreading coefficient) and the area (area of monomer wetting on water surface) of the monomer is wetting the surface of the water, respectively, A S _eq, by wetting Is the interfacial energy to be obtained, and S _eq is the interfacial energy of the fluid / fluid interface. And R represents the radius of the ion conductive inorganic particle.

In the above Equations 1 to 3, cos? _Awp is as shown in Equation 10 below.

[Equation 10]

cos? _awp =? _am /? _aw cos? _amp -? _mw /? _aw cos? _mwp

The contact angle (θ _awp, θ _{amp, wmp} θ) may be measured using a contact angle measuring device.

On the left side of Figure 6d there are five possible structures of the composite membrane. As shown in FIG. 6D, the composite membrane may have A to E phases and their state diagrams are shown on the right.

When the structure of the composite film has the D phase, the monomer layer 620 is covered on the upper part of the particle 600.

The composite membrane according to one embodiment has a C phase. In this case, the particles 600 are uniformly dispersed in the monomer layer 620, and the particles 600 are uniformly present in the monomer layer 620 without pinholes in the composite film, and the composite film has a double continuous structure .

When the structure of the composite membrane has an E phase, the monomer layer 620 and the particles 600 are separated.

The structure of the composite membrane according to one embodiment is mainly determined by the surface tension between air, monomer, water and particles as described above.

The contact angle has an appropriate range if the ion conductive inorganic particles are i) floated in water ii) protruding on the upper and lower surfaces of the monomer layer iii) surrounded by monomers. The contact angles? Wp,? Mp,? Mp represent the contact angles of air / water / particle, air / monomer / particle and water / monomer / particle system, respectively.

The ion conductive inorganic particles are modified to form a hydrophobic coating on the surface, so that when the particles are supplied to the monolayer floated on top of the water, the particles do not submerge in water.

Modification of the surface of the ion conductive inorganic particle can be confirmed by X-ray photonelectronspectroscopy (XPS).

The ratio of the total area of the composite membrane (A _total ) to the _total area of exposed ion conductive inorganic particles (Xp = Ap / A _total ) is 0.05 to 0.5, for example, 0.2 to 0.4. The ionic conductivity of the composite membrane is excellent when it has such a ratio.

A hydrophobic coating film is formed on at least one surface of the ion conductive inorganic particle to form a polymerizable water-insoluble floating compound used for forming an organic film in the process of producing the composite membrane, the first surface of the ion conductive inorganic particle and the second surface Plane. As a result, the composite membrane obtained finally may have a structure in which the ion conductive inorganic particles are exposed on the surface of the composite membrane. ]

The term " first side " refers to the exposed surface of the ion conductive inorganic particles disposed on the upper surface of the composite membrane in Fig. 2, and the term " Represents the surface on which the inorganic particles are exposed.

A hydrophobic coating film is formed on one surface of the ion conductive inorganic particle not exposed to the surface of the composite membrane. One side of the ion conductive inorganic particle not exposed to the surface of the composite membrane may represent the third or fourth side of the ion conductive inorganic particle 21 in FIG. As the hydrophobic coating layer is formed, it is possible to suppress the precipitation of the ion conductive inorganic particles in water during the composite membrane production process, and the ion conductive inorganic particles can be uniformly dispersed in the composite membrane, It is possible to obtain a composite film in a solid state without void space. Further, the formation of the hydrophobic coating film can suppress the covering of the entire surface of the composite film including the upper portion of the hydrophobic coating film from being covered with the organic film forming material such as a polymer.

The hydrophobic coating film may be a continuous coating film state or a discontinuous coating film state such as an island. The formation of the hydrophobic coating film on at least one side of the ion conductive inorganic particles provides an appropriate buoyancy in water.

The arrangement of the hydrophobic coating film on at least one side of the ion conductive inorganic particles can be confirmed by XPS analysis. For example, by the presence of the Si 2p and C 1s peaks of the XPS analysis.

The hydrophobic coating film includes at least one condensation reaction product selected from the group consisting of compounds represented by the following general formula (1).

[Chemical Formula 1]

In the above formula (1), R ₁ to R ₃ independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenyl group, Substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C2-C20 alkynyl groups, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C7- Or a substituted or unsubstituted C2-C20 heteroaryl group, a substituted or unsubstituted C2-C20 heteroaryloxy group, a substituted or unsubstituted C3-C20 heteroarylalkyl group, a substituted or unsubstituted C2-C20 heterocyclic group Or a halogen atom,

R ₄ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group or a substituted or unsubstituted C6-C20 aryl group.

Examples of R ₁ to R ₃ include methyl, ethyl, butyl, isobutyl, octyl, methoxy, ethoxy, octadecyl, 3-methacryloxypropyl, decyl, propyl and chlorine.

R ₄ includes, for example, methyl, ethyl, butyl, propyl, isobutyl, octyl and the like.

Examples of the compound represented by Formula 1 include isobutyltrimethoxysilane, octyltrimethoxysilane, propyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, 3- Perfluorooctyltriethoxysilane and (3-mercaptopropyl) trimethoxysilane from the group consisting of methacryloxypropyltrimethoxysilane, n-octadecyltriethoxysilane, 1H, 1H, 2H, 2H- One or more selected.

The content of the condensation reaction product of the compound represented by the formula (I) in the hydrophobic coating film may be 0.1 to 30 parts by weight, for example, 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the ion conductive inorganic particles to be.

The surface of the composite membrane may include a sea-island structure in which ion conductive inorganic particles are disposed discontinuously in a continuous organic film.

The cross section of the composite membrane may include alternately aligned structures of the organic film and the ion conductive inorganic particles.

The ion conductive inorganic particles embedded in the organic film may be arranged in a monolayer.

The ion conductive inorganic particle has a single particle state without boundary between particles. Thus, grain boundaries of the ion conductive inorganic particles are not observed. The organic film may be a polymer membrane including at least one selected from homopolymers, block copolymers, and random copolymers. The organic film may be a dense film having non-porous characteristics.

Figures 1A and 1B are perspective views schematically illustrating the structure of a composite membrane according to one embodiment.

Referring to this, the composite membrane 10 has a structure in which a polymer membrane 12 in which a plurality of through holes 13 are arranged and ion conductive inorganic particles 11 are inserted and bonded to the through holes 13. The polymer film 12 is one of the organic films as described above. The ion conductive inorganic particles 11 may be hydrophobicized particles formed on at least one side of the hydrophobic coating film (not shown). Here, the hydrophobic coating film may be a continuous coating film state or a discontinuous coating film state such as an island. When the hydrophobic coating film is formed on at least one surface of the ion conductive inorganic particles as described above, appropriate buoyancy in water is provided.

The ion conductive inorganic particles 11 have a structure that penetrates the polymer membrane 12

Are exposed on both sides of the composite membrane (10). Here, the size of the through-hole 13 is controlled in accordance with the size of the ion conductive inorganic particles 11 in the process of manufacturing the composite membrane.

The contact angle of the ion conductive inorganic particles is in the range of 30 to 90 degrees, for example, 30 to 85 degrees.

When the composite membrane of FIG. 1B is used as moisture or a gas permeation preventing film such as oxygen or carbon dioxide of a lithium air cell, ions (for example, lithium ions) pass through ion conductive regions made of ion conductive inorganic particles 11, Is blocked by the polymer membrane (12). Here, the polymer membrane 12 includes a polymer having a property of blocking gases such as moisture, oxygen, and carbon dioxide.

As described above, the ion conductive inorganic particles 11 are exposed from the surface of the composite membrane 10. The exposed area of the ion conductive inorganic particles 11 is 30 to 80%, for example, 40 to 70% based on the total membrane area of the composite membrane. When the ion conductive inorganic particles have the above-described exposed area range, a composite membrane having an excellent ion conductivity can be obtained.

In the composite membrane 10, the thickness of the ion conductive inorganic material particle refers to the height difference between the upper surface and the lower surface of the particle irrespective of the shape of the ion conductive inorganic material particle, and the ion conductive inorganic material particle 11 and the polymer membrane 12 The same thickness. In the case where the ion conductive inorganic particles and the polymer membrane have the same thickness, the composite membrane can be easily bonded to other components and the binding force can be improved.

According to another embodiment, the ion conductive inorganic particles and the polymer may have the same thickness. For example, the thickness of the polymer membrane is about 90 mm, and the thickness of the ion conductive inorganic particle is about 95 mm

The ion conductive inorganic particles 11 form an ion conductive region, and the polymer electrolyte membrane 12 can form a non-ion conductive region. The ion conductive region and the non-ion conductive region are arranged to contact each other in the film thickness direction (Y axis direction) to have a bicontinuous structure.

The term " bicontinuous structure " means a form in which the ion conductive inorganic particles, which are at least one ion conductive region, and the at least one non-ion conductive region, are in contact with each other.

The inorganic ion conductive inorganic particles 11 have a single particle state without intergranular boundaries as shown in FIG. 1A.

Fig. 2 shows a cross section of the composite membrane shown in Fig.

2, when the composite membrane 20 is used as an oxygen permeation preventing film of a lithium air cell, ions (for example, lithium ions) pass through an ion conductive region made of the ion conductive inorganic particles 21 as indicated by a And gas or moisture such as oxygen is blocked by the polymer membrane 22 as shown in b. Here, the polymer membrane 22 includes a polymer having a property of blocking gas such as moisture and oxygen and carbon dioxide.

4 illustrates a structure of a membrane containing LTAP particles 41 embedded in a polymer matrix as a lithium ion transport channel as a composite membrane 40 according to one embodiment.

The membrane provides a selective lithium ion transport pathway derived from buried single LTAP particles without a grain boundary between the particles.

The LTAP particles 41 are surface-modified by PM and IB. And the polymer matrix 42 contains the polymer obtained by the reaction of 4T and TTT.

The composite membrane 40 contains an impermeable polymeric matrix 42 and is flexible and lighter by weight by a factor of 10 compared to the weight of the LTAP membrane. The area resistivity of the composite membrane decreases as the LTAP thickness increases and the composite membrane with lithium ion transport channels exhibits a resistance of 29? Cm ² at about 60 ° C. These composite membranes have excellent barrier properties against oxygen and moisture.

The composite membrane according to one embodiment can be used as a gas permeation preventing film of a lithium air cell, a cathode protecting film of a lithium secondary battery, or the like.

The composite membrane according to one embodiment has a gas permeability of 10 ^-3 to 1,000 cm ³ / m ² day atm. The term " gas " is used herein to mean both oxygen, carbon dioxide, moisture and moisture. The gas permeability refers to, for example, oxygen permeability or water permeability.

The ion conductive inorganic particles are not limited to the shapes shown in Figs. 1A, 1B and 2.

The ion conductive inorganic particle may be, for example, a circular shape, a triangular shape, a quasi-triangular shape, a triangular shape with semi-circles, a triangle having at least one rounded corner a rectangular shape with one or more rounded corners, a square shape, a rectangular shape, a rectangular shape with semi-circles, a polygonal shape, horizontal cross-sectional shapes. The ion conductive inorganic particles may be, for example, cubic, spherical, circular, elliptical, rod, stick, tetrahedral, pyramidal, octahedral, cylindrical, polygonal pillar, polygonal pillar- ), A conical shape, a columnar shape, a tubular shape, a helical shape, a funnel shape, a dendritic shape, a rod shape, etc. It is possible.

The size of the ion conductive inorganic particles indicates the average diameter when the shape of the ion conductive inorganic particles is spherical. When the ion conductive inorganic particles have different shapes, they indicate the length of the long axis.

The ion conductive inorganic particles 11 and 21 have a structure in which the ion conductive inorganic particles penetrate from the front to the back of the polymer membranes 12 and 22 so that the ion conductive inorganic particles are dispersed in the composite membranes 10 and 20 Both surfaces are exposed. If the structure is exposed on both surfaces as described above, the migration path of lithium ions is secured, which is advantageous for improving the conductivity of the composite film.

In the conventional lithium air battery, ion conduction and oxygen barrier function were simultaneously performed using a ceramic material film. However, such a ceramic material film is large in weight, difficult to be large in area, and is limited in the shape of the film. In addition, it is not only weak in mechanical strength like a phenomenon that it is easily broken by external impact, but also limits the weight or thickness of the membrane.

As shown in FIGS. 1A, 1B, and 2, the composite membrane according to one embodiment is excellent in ion conductivity because the ion conductive inorganic particles are exposed on the surface of the composite membrane to allow passage of ions. The hydrophobic coating film is formed on at least one surface of the ion conductive inorganic particle to improve the dispersibility of the ion conductive inorganic particle in the composite membrane and to form a structure in which the ion conductive inorganic particle is exposed on the surface of the composite membrane finally obtained There is an easy advantage. In addition, compared with the conventional ceramic material film, it is possible to reduce the thickness, thereby reducing the resistance and making it lightweight and large. In addition, the composite membrane has excellent flexibility due to the presence of the polymer, which allows it to be processed as desired, thus allowing free cell design and excellent mechanical strength.

According to one embodiment, when the composite membrane includes moisture or moisture, and a polymer having a property of blocking gases such as oxygen and carbon dioxide, the ability to block moisture, moisture, and gas is excellent. Therefore, such a composite membrane can be manufactured at a lower cost than a conventional ceramic material membrane. By adopting such a composite membrane, it is possible to make it large-sized, thin, lightweight, and easy to manufacture. By using such a composite membrane, a lithium secondary battery having an improved lifetime can be manufactured.

Ion conductive region and a non-ion conductive region are disposed in contact with each other in the film thickness direction (Y-axis direction) to have a bicontinuous structure, the ion conductive region and the non- There is provided a composite film comprising an ion conductive inorganic particle in which an ion conductive region has a hydrophobic coating film disposed on at least one side thereof, and the non-ion conductive region includes a polymer. Here, the ion conductive inorganic particles have a single particle state without a grain boundary.

The ion conductive inorganic particles are exposed on the surface of the composite membrane and have excellent ion conductivity and excellent flexibility, so that they have excellent mechanical strength and can be processed as desired.

The ion conductive inorganic particles include, for example, lithium ion conductive inorganic particles.

The content of the ion conductive inorganic particles having the hydrophobic coating film formed on at least one surface thereof is 10 to 90 parts by weight, for example, 20 to 80 parts by weight, based on 100 parts by weight of the total weight of the composite membrane. When the content of the ion conductive inorganic particles in which the hydrophobic coating film is formed is within the above range, a composite membrane having excellent ion conductivity and mechanical strength can be obtained.

Wherein the ion conductive inorganic particle is at least one selected from the group consisting of a glassy active metal ion conductor, an amorphous active metal ion conductor, a ceramic active metal ion conductor, and a glass-ceramic active metal ion conductor. It is a combination.

The ion conductive inorganic particle may be, for example, Li _{1 + x + y} Al _x Ti _{2 - x} Si _y P _{3 - y} O ₁₂ (0 <x <2, 0≤y <3), BaTiO 3, Pb (Zr, Ti) O 3 (PZT), Pb 1 - x La x Zr 1 -y Ti y O 3 (PLZT) (O≤x <1, O≤y <1), PB (Mg 3 Nb 2/3) O 3 -PbTiO 3 (PMN-PT), HfO 2, SrTiO 3, SnO 2, CeO 2, Na 2 O, MgO, NiO, _{CaO, BaO, ZnO, ZrO 2} , y 2 O 3, Al 2 O 3, TiO 2, SiO 2, SiC, lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(Li x Ti y (PO 4} ) 3, 0 <x <2, 0 < y <3), lithium aluminum titanium phosphate _{(Li x Al y Ti z (} PO 4) 3, 0 <x <2, 0 <y <1, 0 <z <3), Li _{1 + x + y (Al,} Ga) x (Ti, Ge) 2 - x Si y P 3 - y O 12 (O ◎ x ◎ 1, O≤y≤1), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (LixGeyPzSw, 0 <x <4, 0 <y <1, 0 <z <

(Li _x N _y , 0 <x <4, 0 <y <2), SiS ₂ (Li _x Si _y S _z , 0 <x <3, 0 <y <2, 0 <z < 4), P ₂ S ₅ series glasses (Li _x P _y S _z , 0 <x <3, 0 <y <3, 0 <z <7), Li ₂ O, LiF, LiOH, Li ₂ CO ₃ , LiAlO ₂ , Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ ceramics, Garnet ceramics Li _{3 + x} La ₃ M ₂ O ₁₂ (M = Te, Nb, Or Zr) (x is an integer of 1 to 10), or a combination thereof.

Garnet-based ceramics include, for example, Li ₇ La ₃ Zr ₂ O ₁₂ and the like.

As the ion conductive inorganic _{particles, LTAP (Li 1. 4 Ti} 1. 6 Al 0. 4 P 3 O 12), or _{Li 2 O-Al 2 O 3} -SiO 2 -P 2 O 5 -TiO 2 -GeO 2 Based ceramics can be used.

As described above, since the ion conductive inorganic particles do not have intergranular boundaries as described above, the composite membrane containing such ion conductive inorganic particles can secure a lithium conductive path with a small resistance. As a result, conduction and migration of lithium ions becomes very easy, and the conductivity and lithium ion transmission rate of lithium ions are remarkably improved. It is superior in flexibility and mechanical strength compared to a membrane made of inorganic particles.

It can be confirmed by scanning electron microscope (SEM) that the ion conductive inorganic particle is a single particle state without boundary between particles.

The average particle diameter of the ion conductive inorganic particles is 1 to 300 탆, for example, 1 to 200 탆, specifically 1 to 150 탆. When the average particle diameter of the ion conductive inorganic particles is within the above range, a composite film containing ion conductive inorganic particles in a single particle state free from grain boundaries can be easily obtained through polishing or the like during the production of a composite film.

The ion conductive inorganic particles have a uniform size and maintain a uniform size in the composite membrane. For example, the ion conductive inorganic particle has a D50 of 110 to 130 mu m and a D90 of 180 to 200 mu m. D10 is 60 to 80 mu m. Here, the terms D50, D10 and D90 refer to particle sizes (particle diameters) respectively representing 50 vol%, 10 vol% and 90 vol% in the cumulative distribution curve.

The polymer constituting the composite membrane may be variously selected depending on the use of the composite membrane.

If the polymer has a barrier property to block at least one selected from oxygen and moisture, the composite membrane has a property of blocking anode corrosive gases, for example. Examples of the negative-electrode corrosive gas include water vapor, carbon dioxide, oxygen, and the like. Accordingly, the composite membrane can function as an oxygen barrier membrane, a moisture blocking membrane, or a carbon dioxide barrier membrane.

Examples of the polymer having a barrier property for blocking gases and water or moisture include a polymer obtained by a polymerization reaction of a polymerizable water-insoluble floating compound.

The polymerizable water-insoluble floating compound is a polymerizable organic monomer having a floating property in water and possessing non-volatile and water-insoluble properties, and is a substance having two or more polymerizable functional groups. The polymerization here includes both copolymerization and crosslinking. The polymerizable water-insoluble floating compound includes, for example, at least one polyfunctional monomer selected from i) a polyfunctional acrylic monomer and a polyfunctional vinyl monomer, or ii) at least one polyfunctional monomer selected from polyfunctional acrylic monomers and polyfunctional vinyl monomers And mixtures of polythiols having three or four thiol groups.

The above-mentioned floating compound means a hydrophobic compound.

The polyfunctional acrylic monomer may be selected from the group consisting of diurethane dimethacrylate, trimethylolpropane triacrylate, diurethane diacrylate, trimethylolpropane trimethacrylate, neopentyl glycol diacrylate, 3'-acryloxy-2 ', 2'-dimethylpropyl 3-acryloxy-2,2-dimethylpropionate (3'- And bisphenol A acrylate.

Examples of multifunctional vinyl-based monomers include 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione (1,3,5-triallyl-1,3,5-triazine -2,4,6-trione), 3-methacrylpropyltrimethoxysilane, and the like.

The polythiol may be selected from the group consisting of pentaerythritol tetrakis (3-mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), 4-mercaptomethyl- 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (2-mercaptoacetate) ), Trimethylolpropane tris (2-mercaptoacetate).

The organic film includes a polymerization product of pentaerythritol tetrakis (3-mercaptopropionate) and 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione .

The polymerizable water-insoluble floating compound has a solubility in water of 0.0001 to 0.025 g / l. When the polymerizable water insoluble floating compound is pentaerythritol tetrakis (3-mercaptopropionate), the solubility of the compound in water is about 0.00369 g / l, and when the polymerizable water insoluble floating compound is TTT When the solubility in water is 0.001 g / l, and in the case of trimethylolpropane trimethacrylate, the solubility in water is about 0.0201 g / l.

According to another embodiment, the composite membrane may be used as a cathode protection layer of a lithium secondary battery such as a lithium sulfur secondary battery or an aqueous lithium ion secondary battery. In addition, composite membranes can be used to improve the performance of lithium ion batteries by separating the anode and cathode electrolytes and to increase the possibility of employing new materials.

When the composite membrane is used as a lithium sulfur secondary battery or a water-based lithium ion secondary cell protective film, the polymer forms a non-ionic conductive region.

The content of the polymer in the composite membrane is 10 to 80 parts by weight, for example, 50 to 80 parts by weight, based on 100 parts by weight of the total weight of the composite membrane. When the content of the polymer is within the above range, a composite membrane excellent in lithium ion conductivity, flexibility and gas barrier property can be obtained without deteriorating the film formability of the composite film.

The polymer has a weight average molecular weight of 10,000 to 300,000. The weight average molecular weight is measured by Gel Permeation Chromatography (GPC). When the weight average molecular weight of the polymer is within the above range, it is possible to produce a composite membrane having excellent ionic conductivity, moisture and gas barrier properties without lowering the film-forming property.

Since the composite membrane contains ion conductive inorganic particles at a high density, the resistance of the composite membrane is very small.

Composite membranes according to one embodiment have a weight ranging from 5 to 20 mg / cm ² , such as 11 to 16 mg / cm ² . By using such a composite membrane, a thinned and lightweight battery can be produced.

The thickness of the composite membrane is 10 to 200 占 퐉, for example, 70 to 100 占 퐉. With such a thickness range, the ionic conductivity and moisture and gas barrier properties of the composite membrane are excellent.

The composite membrane may further comprise a porous substrate.

The porous substrate is excellent in mechanical properties and heat resistance and can be used as long as it has pores therein.

Examples of the porous substrate include olefin-based polymers having excellent chemical resistance and hydrophobicity; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used.

 Specific examples of the olefin polymer include polyethylene / polypropylene two-layer separator, polyethylene / polypropylene / polyethylene three-layer separator, polypropylene / polyethylene / polypropylene three-layer separator Or the like can be used.

The porous substrate may specifically be a polyethylene film, a polypropylene film or a combination thereof. The pore diameter of the porous substrate is, for example, 0.01 to 10 mu m and the thickness is, for example, 5 to 35 mu m. Such a porous substrate may contain an electrolytic solution containing a lithium salt and an organic solvent.

The content of the lithium salt is used in a concentration of 0.01 to 5M, for example, 0.2 to 2M. When the content of the lithium salt is in the above range, the composite film has excellent conductivity.

The lithium salt may dissolve in a solvent and act as a source of lithium ions in the cell. Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ C ₂ F ₅ ) ₂ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , LiClO ₄ , LiAlO ₂ , _{LiAlCl 4, LiN (C x F} 2x + 1 SO 2) (C y F 2y + 1 SO 2) ( where, x and y are natural numbers), LiF, LiBr, LiCl, LiOH, LiI , and LiB (C ₂ O ₄ ) ₂ (lithium bis (oxalato) borate (LiBOB)) may be used.

Other metal salts other than the lithium salt may be further included, for example, AlCl ₃ , MgCl ₂ , NaCl, KCl, NaBr, KBr, and CaCl ₂ .

The polymerizable water-insoluble floating compound solution is floated in water, followed by about 90% blocking with a cover, allowing the solvent to slowly evaporate over 1 hour. When dried at this rate, a composite membrane having the desired contact angle can be produced.

The ion conductive particles are dried at a temperature of 25 to 100 DEG C, for example, about 60 DEG C for 2 hours or less, for example, about 30 minutes before spreading. The moisture content of the ion conductive inorganic particles after the drying process is controlled to be not more than 100 ppm, for example, in the range of 0.00001 to 100 ppm. As described above, when the ion conductive inorganic particles having controlled moisture content are used, a composite membrane having a desired contact angle can be obtained.

Hereinafter, a method for producing a composite membrane according to one embodiment will be described.

First, a first step is carried out in which a mixture containing a polymerizable non-aqueous floating compound and a solvent and an ion conductive inorganic particle having a hydrophobic coating film formed on at least one surface thereof are floated. The ion conductive inorganic particle may be a hydrophobic particle formed by forming a hydrophobic coating film on at least one surface.

The ion conductive inorganic particles are dried to control the moisture content to 100 ppm or less before the flooding step is carried out. By using the ion conductive inorganic particles having such a water content, a composite membrane having a desired contact angle can be produced.

The drying step for controlling the moisture content of the ion conductive inorganic particles to 100 ppm or less is carried out under vacuum at 100 캜 or lower, for example, at 30 to 60 캜. The drying time depends on the temperature for drying, but is carried out, for example, in the range of 10 hours or less, for example, 0.5 to 5 hours.

The solvent may be any solvent capable of dissolving and / or dispersing a polymerizable water-insoluble floating compound. Examples of the solvent include alcohols such as methanol, ethanol, chloroform, methylene chloride, methyl ethyl ketone, acetonitrile, acetone, formamide, dimethylformamide, tetrahydrofuran, N-methyl-2-pyrrolidinone, At least one selected from dioxolane, sulfolane, dimethylsulfolane, acetyl acetate, benzene, toluene, 1,2-dichloroethane and hexane can be used.

The content of the polymerizable water-insoluble floating compound is 10 to 1000 parts by weight, for example, 150 to 900 parts by weight, based on 100 parts by weight of the ion conductive inorganic particles. When the content of the polymerizable water-insoluble floating compound is within the above range, a composite membrane having excellent ionic conductivity without deteriorating water and gas barrier properties can be produced.

A second step of stirring the resultant, and a third step of removing the solvent from the resultant product. Then, a fourth step of applying heat or light to the resultant product obtained in the third step to carry out the polymerization reaction is carried out.

In the first step, the order of floating the polymerizable water-insoluble floating compound and the ion conductive inorganic particles in water can be varied in various ways. For example, the first step is a floating casting step in which a mixture comprising a polymerizable water-insoluble floating compound and a solvent is floated; And a floating casting step of floating the ion conductive inorganic particles in water by providing an ion conductive inorganic particle having a hydrophobic coating film on at least one surface thereof.

For example, the first step includes a floating casting step in which a mixture of a monomer containing a polymerizable water-insoluble floating compound and a solvent and an ion conductive inorganic particle having a hydrophobic coating film formed on at least one side thereof are simultaneously exposed to water.

For example, the first step is a step of flooding an ion conductive inorganic particle having a hydrophobic coating film formed on at least one side thereof in water; And a floating casting step of immersing the resultant in water by mixing a monomer mixture containing a polymerizable non-aqueous floating compound and a solvent.

According to one embodiment, the first step comprises: a-1) floating casting in which a portion of the mixture comprising the polymerizable water-insoluble floating compound and the solvent is floated; a-2) a floating casting step of ion-conducting inorganic particles having a hydrophobic coating film formed on at least one side of the resultant product to float the ion conductive inorganic particles in water; a-3) flooding the remainder of the mixture comprising the water-insoluble floating compound capable of polymerization to the resultant and the solvent in water. A part of the polymerizable water-insoluble floating compound is first cast on a water surface to provide an ion conductive inorganic particle having a hydrophobic coating film formed thereon. The remaining polymerizable water-insoluble floating compound is then subjected to a second floating casting on the water surface. Through these steps, the polymerizable non-aqueous floating compound and the ion conductive inorganic particles can be uniformly dispersed, and the polymerizable non-aqueous floating compound fills the space between the ion conductive inorganic particles by capillary force. As a result, it is possible to obtain a composite membrane having a structure in which ion conductive inorganic particles having a hydrophobic coating film formed on a plurality of through holes in a polymer membrane are filled. The feed amount of the polymerizable water-insoluble floating compound in the first floating casting step is in the range of 30 to 60% based on the total feed amount, and the feed amount of the polymerizable water-insoluble compound in the second floating casting step is in the range of 40 to 70 %.

In the first step, when the mixture containing the polymerizable non-aqueous floating compound and the solvent and the ion conductive inorganic particles formed with the hydrophobic coating film are floated on the water, they can be simultaneously floated on the water. Or the mixture is floated first, and then the ion conductive inorganic particles having the hydrophobic coating film formed thereon are floated in water.

FIG. 5 is intended to explain the manufacturing process of the composite membrane 50 according to one embodiment. Referring to this, the polymerizable non-aqueous floating compound 54 is floated on the water 53, and the ion conductive inorganic particles 51 having the hydrophobic coating film formed thereon are floated on the resultant product.

The second step of stirring the resultant product is a step of performing air blowing. The air blowing step refers to a process of supplying an inert gas such as air or nitrogen or argon gas. When the air obtained by the first step is subjected to air application, the non-aqueous floating compound floating on the surface of the water and the ion conductive inorganic particles are stirred to form a polymer having a plurality of through holes, A composite membrane including conductive inorganic particles and having a structure in which the ion conductive inorganic particles are exposed on the surface has excellent ionic conductivity and water and gas barrier properties can be obtained.

The third step of removing the solvent from the resultant may be performed at room temperature (25 ° C) to 60 ° C, for example. When the solvent is removed, a thin film of a polymerizable floating compound is embedded in the ion conductive inorganic particle having the hydrophobic coating film formed thereon.

The solvent is removed, and then a heat or light is applied to perform a polymerization reaction. After the fourth step, polymerization of the polymerizable flocculent compound proceeds.

When the above-mentioned polymerization reaction is completed, the resultant is lifted off from the water. The composite membrane 50 in which the hydrophobic coating film is formed in the polymer membrane 52 and the surface-modified ion conductive inorganic particles 51 are embedded can be manufactured.

A polymerization initiator may be added to the mixture containing the polymerizable water-insoluble floating compound and the solvent. As such a polymerization initiator, a photopolymerization initiator or a thermal polymerization initiator may be used.

The photopolymerization initiator can be used without limitation in the constitution as long as it is a compound capable of forming a radical by light such as ultraviolet rays. Examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP), benzoin ether, dialkyl acetophenone, At least one member selected from the group consisting of hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl phosphine and alpha-aminoketone, Can be used. On the other hand, as a specific example of the acylphosphine, a commonly used lucyrin TPO, i.e., 2,4,6-trimethyl-benzoyl-trimethyl phosphine oxide can be used .

As the thermal polymerization initiator, at least one selected from persulfate-based initiators, azo-based initiators, initiators consisting of hydrogen peroxide and ascorbic acid can be used. Specifically, examples of persulfate-based initiators include sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4) 2S2O8, and the like. Azo Examples of the initiator include 2, 2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis- (N, N-dimethylene) isobutane Azobis- (N, N-dimethylene) isobutyramidine dihydrochloride, 2- (carbamoyl azo) isobutylonitrile, 2, 2-azobis Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride), 4,4-azobis- ( 4-azobis- (4-cyanovaleric acid), and the like.

The polymerization initiator may be contained in an amount of 0.005 to 10.0 parts by weight based on 100 parts by weight of the polymerizable floating compound. When the content of the polymerization initiator is within the above range, the reactivity of the polymerization reaction of the polymerizable floating compound is excellent.

The light may be ultraviolet (UV). When the polymerization reaction is carried out using light as described above, it is possible to prevent the lithium metal thin film from being deformed by heat when the composite film is formed on the lithium metal thin film. An electrolyte may be formed between the lithium metal thin film and the composite film.

The time for carrying out the polymerization (crosslinking) reaction by applying light or heat is variable but can be, for example, from 1 minute to 30 minutes.

When heat is applied, the heat treatment depends on the type of the polymerizable floating compound and the like, and may be carried out, for example, at 60 to 200 ° C. As another example, the heat treatment may be carried out at 60 to 100 캜.

The ion conductive inorganic particle having the hydrophobic coating film formed on at least one side thereof is reacted with b-1) ion conductive inorganic particles and a compound represented by the following formula 1 and b-2) washing and drying the reaction product .

 [Chemical Formula 1]

In the above formula (1), R ₁ to R ₃ independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenyl group, Substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C2-C20 alkynyl groups, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C7- Or a substituted or unsubstituted C2-C20 heteroaryl group, a substituted or unsubstituted C2-C20 heteroaryloxy group, a substituted or unsubstituted C3-C20 heteroarylalkyl group, a substituted or unsubstituted C2-C20 heterocyclic group Or a halogen atom,

R ₄ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group or a substituted or unsubstituted C6-C20 aryl group.

The ion conductive inorganic particles used in the step b-1) may be subjected to grinding and sieving to have an average particle size of 1 to 300 μm, for example, 1 to 200 μm, specifically 1 to 100 μm .

The size of the ion conductive inorganic particles is a very important factor for the ion conductivity of the composite membrane. Therefore, the size of the ion conductive inorganic particles is appropriately controlled so as to have a uniform particle state. For this purpose, only ion conductive inorganic particles having a desired average particle diameter are collected through sieving of ion conductive inorganic particles.

The average particle diameter of the ion conductive inorganic particles is 1 to 300 탆, for example, 1 to 200 탆, specifically 1 to 100 탆. According to one embodiment, the average particle diameter of the ion conductive inorganic particles is 90 to 200 占 퐉, for example, 90 to 100 占 퐉.

According to one embodiment, the ion conductive inorganic particles may be further subjected to a process of pulverizing and classifying the ion conductive inorganic particles so that the average particle diameter of the ion conductive inorganic particles is in the range of 1 to 300 μm before reacting with the compound of formula (1).

For milling, beads mill or the like is used. A bead is used in the pulverization process, for example, the particle diameter of the beads is 0.5 to 2 mm, and the number of revolutions per minute of the pulverizer is, for example, 1000 to 2000 rpm. When the particle diameter of the beads and the number of revolutions per minute of the pulverizer are in the above range, the pulverization of LTAP can be suppressed.

Examples of the material of the beads include, but not limited to, zirconia beads or alumina beads.

The ion conductive inorganic particles and the compound represented by Formula 1 may be carried out by using an impregnation method, a spray method, a ball mill method, or the like.

According to one embodiment, the step of reacting the ion conductive inorganic particles and the compound represented by Formula 1 may include a step of reacting the ion conductive inorganic particles, the compound represented by Formula 1, and the solvent at room temperature (25 ° C) Lt; RTI ID = 0.0 &gt; C &lt; / RTI &gt; and removing the solvent therefrom.

The step of reacting the ion conductive inorganic particles and the compound represented by the formula (1) is carried out, for example, for 20 hours or less, for example, 3 to 10 hours.

According to another embodiment, the reaction between the ion conductive inorganic particle and the compound represented by Formula 1 is performed by spraying a composition containing the compound represented by Formula 1 and a solvent on the surface of the ion conductive inorganic particle using a spraying method Followed by mixing.

When the impregnation method and the spray method are carried out, the solvent may be an organic solvent such as toluene, methylene chloride, methanol, ethanol, propanol, ethyl acetate , And diethyl ether may be used.

The step of washing the reaction product may be performed using a solvent such as acetone. And the drying step may be performed at room temperature (25 캜) to 85 캜.

According to the above process, an ion conductive inorganic particle having a hydrophobic coating film formed on at least one surface thereof is obtained. These ion conductive inorganic particles have hydrophobicity, and the hydrophobic coating film has a continuous or discontinuous coating film state, and the coating film thickness is, for example, 1 to 100 nm. Thus, even if the hydrophobic coating film is formed on the surface of the ion conductive inorganic particles, the ion conductivity does not decrease due to the formation of the hydrophobic coating film, because the thickness of the hydrophobic coating film is relatively thin compared to the total thickness of the composite film.

The thickness of the hydrophobic coating film is 1 to 80 nm, for example, 1 to 50 nm, specifically 1 to 15 nm. According to one embodiment, the thickness of the hydrophobic coating film is 1 to 10 nm.

The thickness of the composite film is 10 to 200 占 퐉, for example, 70 to 100 占 퐉.

The composite membrane is a lithium ion conductive film that protects a cathode capable of intercalating and deintercalating lithium ions, and can selectively serve as a protective film for preventing other substances from reacting with the cathode by selectively transmitting lithium ions. In addition, the protective film has a reduced resistance and improved ionic conductivity due to the thinning of the protective film.

The composite membrane may be used as a protective film or an oxygen permeation preventing film of a lithium air cell, a protective film of a lithium sulfur battery, a protective film and a separator of an aqueous lithium ion battery, or a separator of a fuel cell.

According to another aspect there is provided a cathode structure comprising a cathode and a composite membrane as described above.

The negative electrode structure may further include an electrolyte between the negative electrode and the composite membrane.

3A schematically illustrates the structure of a cathode structure according to one embodiment.

Referring to FIG. 3, the cathode structure has a structure in which an electrolyte 320 is disposed between the cathode 310 and the composite membrane 330. Here, the electrolyte 320 may be omitted.

As the cathode 310, for example, a lithium metal thin film can be used, and the composite film can serve as a lithium metal protective film. Accordingly, the composite membrane according to one embodiment is excellent in flexibility and light weight and excellent in oxygen barrier property.

As the electrolyte, an aqueous electrolyte or a non-aqueous electrolyte may be used. These electrolytes may be the same as the electrolytes used in the production of lithium air cells described later.

According to another aspect, there is provided a lithium secondary battery comprising the composite membrane described above.

The lithium secondary battery is, for example, a lithium air battery. A lithium air battery includes a cathode, a composite membrane, and a cathode having oxygen as a cathode active material.

The lithium air battery may use an aqueous electrolyte or a non-aqueous electrolyte as an electrolyte existing between the positive electrode and the negative electrode.

When a non-aqueous electrolyte is used as the electrolyte, the following reaction mechanism can be shown.

<Reaction Scheme 1>

_{4Li + O 2 → 2Li 2 O} E o = 2.91V

₂ Li + O ₂ Li ₂ O ₂ E ^o = 3.10 V

At the time of discharging, lithium derived from the cathode meets with oxygen introduced from the anode to produce lithium oxide, and oxygen is reduced. On the contrary, on charging, lithium oxide is reduced and oxygen is oxidized.

The shape of the lithium air battery is not particularly limited and may be, for example, a coin shape, a button shape, a sheet shape, a laminate shape, a cylindrical shape, a flat shape, a horn shape or the like. It can also be applied to large-sized batteries used in electric vehicles and the like.

FIG. 3B schematically illustrates a lithium air battery according to one embodiment.

The lithium air battery 30 has a structure in which a composite membrane 35 according to an embodiment is disposed between an anode 37 made of oxygen as an active material and a cathode 33 formed on the substrate 32. An electrolyte (34) may be disposed between the cathode (33) and the composite membrane (35). The cathode 33, the electrolyte 34 and the composite membrane 35 constitute a protective cathode.

The electrolyte (34) is excellent in the conductivity of lithium ion and has a small resistance per unit area when combined with a negative electrode.

The lithium ion conductive solid electrolyte membrane or the separator may be further included between the cathode 33 and the electrolyte 34 or between the electrolyte 34 and the composite membrane 35.

The positive electrode 37 includes a current collector on which a pressing member 39 capable of transmitting air to the positive electrode 37 is disposed. As shown in FIG. 3B, a case 31 made of an insulating resin material containing the positive electrode 37 and the negative electrode 33 is interposed. The air is then supplied to the air inlet 38a and discharged to the air outlet 38b.

As used herein, the term "air" is not meant to be limited to atmospheric air, but may include a combination of gases containing oxygen, or pure oxygen gas.

An electrolyte (36) is disposed between the composite membrane (35) and the anode (37).

A lithium ion conductive solid electrolyte membrane or separator may be further included between the anode 37 and the electrolyte 36 or between the electrolyte 36 and the composite membrane 35.

The composite film 35 is formed on the surface of the cathode 33 so as to serve as a protective film for protecting lithium of the cathode 33 from the electrolyte.

The composite film 35 may be used as a single layer or a multilayer film.

As the electrolytes (34) and (36), a polymer solid electrolyte can be used. LiBF ₄ , LiPF ₆ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ and LiN (SO ₂ CF ₃ ) _{2 are used} as the lithium salt. (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ , LiN (SO ₂ F) ₂ , LiC ₄ F ₉ SO ₃ and LiAlCl ₄ .

According to another embodiment, the electrolytes 34 and 36 may be liquid electrolytes comprising a solvent and a lithium salt.

As the solvent, at least one selected from an aprotic solvent and water is used.

As the aprotic solvent, a carbonate, ester, ether, ketone, amine or phosphine solvent may be used.

Examples of the carbonate solvent include dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC) EC), propylene carbonate (PC), and butylene carbonate (BC).

Examples of the ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, butyl acetate, methyl propionate, ethyl propionate,? -Butyrolactone, decanolide, valerolactone, mevalono Mevalonolactone, caprolactone, and the like may be used.

As the ethereal solvent, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran and the like can be used. As the ketone solvent, cyclohexanone and the like can be used.

As the amine-based solvent, triethylamine, triphenylamine and the like can be used. As the phosphine-based solvent, triethylphosphine or the like may be used, but not always limited thereto, and any aprotic solvent that can be used in the technical field is possible.

Examples of the aprotic solvent include nitriles such as R-CN (R is a linear, branched, or cyclic hydrocarbon group having 2 to 30 carbon atoms and may include a double bond, an aromatic ring, or an ether bond) Amides such as dimethylformamide, dioxolanes such as 1,3-dioxolane, and sulfolanes.

The non-protonic solvents may be used singly or in a mixture of one or more, and the mixing ratio of one or more of them may be appropriately adjusted depending on the performance of the battery, which is obvious to a person skilled in the art.

In addition, the electrolytes 34 and 36 may comprise an ionic liquid.

The ionic liquid is a straight, branched, substituted ammonium, imidazolium, pyrrolidinium pyridinium, piperidinium cations and _{^{PF 6 -, BF 4 -,}} CF 3 SO 3 -, (CF 3 SO 2) 2 N - , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (FSO ₂ ) ₂ N ^- , (CN) ₂ N ^- and the like.

Some or all of the electrolytes (34) and (36) may be impregnated into the anode or cathode.

According to another embodiment, as the electrolytes 34 and 36, a lithium ion conductive solid electrolyte membrane can be used.

The lithium ion conductive solid electrolyte film may be an inorganic material containing lithium ion conductive glass, lithium ion conductive crystal (ceramic or glass-ceramic), or a mixture thereof. In consideration of chemical stability, the lithium ion conductive solid electrolyte membrane contains an oxide.

When the lithium ion conductive solid electrolyte membrane contains a large amount of lithium ion conductive crystals, a high ion conductivity is obtained. For example, lithium ion conductive crystals may be added to the solid electrolyte membrane in an amount of, for example, 50 wt% or more and 55 wt% By weight or more, or 60% by weight or more.

Examples of the lithium ion conductive crystals include Li ₃ N, LISICON, La _{0 . 55} Li _{0 . 35} TiO ₃ , LiTi ₂ P ₃ O ₁₂ having a NASICON structure, or a glass-ceramics for precipitating these crystals can be used.

The lithium ion conductive crystal as, for _{example, Li 1 + x + y (} Al, Ga) x (Ti, Ge) 2 -x Si y P 3-y O 12 ( stage, O≤x≤1, O≤y≤ 1, for example, 0? X? 0.4, 0 <y? 0.6, or 0.1? X? 0.3 and 0.1 <y? 0.4). In order for the lithium ion conductive crystal to have a high ion conductivity, the lithium ion conductive crystal should not have grain boundaries that do not conduct ion conduction. For example, since glass-ceramics have few pores or grain boundaries that interfere with ion conduction, they can have high ionic conductivity and excellent chemical stability.

Examples of the lithium ion conductive glass-ceramics include lithium-aluminum-germanium-phosphate (LAGP), lithium-aluminum-titanium-phosphate (LATP), and lithium- aluminum- titanium-silicon- phosphate have.

For example, when the mother glass has a composition of Li ₂ O-Al ₂ O ₃ -TiO ₂ -SiO ₂ -P ₂ O ₅ and the mother glass is crystallized by heat treatment, the main crystal phase is Li _{1 + x + y} Al _x Ti _{2 - x} Si _y P _{3 - y} O ₁₂ (0? x? 2, 0? y? ₃ ), where x and y are, for example, 0? x? 0.6, or 0.1? X? 0.3, and 0.1 <y? 0.4.

Here, the pores or grain boundaries that interfere with the ion conduction are meant to mean that the conductivity of the entire inorganic material including the lithium ion conductive crystal is reduced to 1/10 or less of the conductivity of the lithium ion conductive crystal itself in the inorganic material Or an ionic conductivity inhibitor such as a grain boundary system.

On the other hand, a conductive material can be used as an anode using oxygen as a cathode active material. The conductive material may be porous. Therefore, any material having the above-described porosity and conductivity can be used as the positive electrode active material without limitation, and for example, a carbon-based material having porosity can be used. Examples of such carbon-based materials include carbon blacks, graphites, graphenes, activated carbons, and carbon fibers.

As the cathode active material, a metal conductive material such as a metal fiber or a metal mesh may be used. Further, as the cathode active material, a metallic powder such as copper, silver, nickel, or aluminum may be used. And organic conductive materials such as polyphenylene derivatives can be used. The conductive materials may be used alone or in combination.

A catalyst for oxidation / reduction of oxygen may be added to the anode. Examples of the catalyst include noble metal catalysts such as platinum, gold, silver, palladium, ruthenium, rhodium and osmium, manganese oxide, iron oxide, cobalt oxide, nickel Oxides and the like, or organometallic catalysts such as cobalt phthalocyanine may be used. However, the present invention is not limited thereto, and any catalyst that can be used as an oxidation / reduction catalyst for oxygen in the related art can be used.

In addition, the catalyst may be supported on a carrier. The carrier may be an oxide, zeolite, clay minerals, carbon, or the like. The oxide may include one or more oxides such as alumina, silica, zirconium oxide, and titanium dioxide. Or an oxide comprising at least one metal selected from Ce, Pr, Sm, Eu, Tb, Tm, Yb, Sb, Bi, V, Cr, Mn, Fe, Co, Ni, Cu, . The carbon may be carbon black such as Ketjen black, acetylene black, tan black, lamp black, graphite such as natural graphite, artificial graphite and expanded graphite, activated carbon, carbon fiber and the like, Anything that can be used as a carrier in the field is possible.

The anode may further include a binder. The binder may include a thermoplastic resin or a thermosetting resin. For example, it is possible to use polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, vinylidene fluoride- Vinylidene fluoride copolymer, fluoroethylene copolymer, fluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymer, Ethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene- Acrylic acid copolymer and the like can be used singly or in combination, but they are not limited to these, Anything that can be used as a binder in the technical field is possible.

For example, the anode may be prepared by mixing the oxygen oxidation / reduction catalyst, the conductive material and the binder, and then adding a suitable solvent to prepare a cathode slurry. The anode slurry is coated on the surface of the current collector, dried, And then compression-molding the entire body. In addition, the anode may optionally comprise lithium oxide. Alternatively, the oxygen oxidation / reduction catalyst may be optionally omitted.

As the current collector, it is possible to use a porous body such as a mesh or mesh in order to accelerate the diffusion of oxygen, and a porous metal plate such as stainless steel, nickel, or aluminum can be used. However, the present invention is not limited thereto. Anything that can be used is possible. The current collector may be coated with an oxidation-resistant metal or alloy coating to prevent oxidation.

The negative electrode comprising lithium as a negative electrode in the lithium air battery may be an electrode containing a substance capable of occluding and releasing Li metal, Li metal-based alloy, or Li, but is not limited thereto and may be used as a negative electrode in the related art And any material capable of containing lithium or capable of intercalating and deintercalating lithium can be used. The cathode determines the capacity of the lithium air battery.

The cathode may be, for example, a lithium metal thin film. Examples of the lithium metal-based alloy include at least one selected from the group consisting of aluminum, tin, magnesium, indium, calcium, titanium, and vanadium, and an alloy of lithium.

It is also possible to dispose a separator between the positive electrode and the negative electrode. The separator is not limited as long as it can withstand the range of use of the lithium air battery. For example, a polymer nonwoven fabric such as a nonwoven fabric of polypropylene material or a nonwoven fabric of polyphenylene sulfide material, an olefin resin such as polyethylene or polypropylene And a combination of two or more of them may be used.

The lithium air battery according to one embodiment improves the non-capacity and life characteristics by adopting the composite membrane described above.

The lithium secondary battery according to one embodiment includes, for example, a lithium sulfur secondary battery or a lithium ion secondary battery.

A lithium secondary battery employing a composite membrane according to one embodiment as a lithium metal protective film is as shown in FIG. 3C.

The lithium secondary battery 61 includes an anode 63, a cathode 62, and a separator 64. The anode 63, the cathode 62 and the separator 64 described above are wound or folded and housed in the battery case 65. Then, the organic electrolyte is injected into the battery case 65 and the cap assembly 66 is sealed to complete the lithium secondary battery 61.

The battery case may be cylindrical as shown in FIG. 3C, or it may be square, thin film, or the like. For example, the lithium secondary battery may be a thin film battery.

A battery structure is formed by disposing a separator 64 between the anode 63 and the cathode 62. The cell structure is laminated in a bi-cell structure, then impregnated with the organic electrolyte, and the obtained result is received in the pouch When sealed, a pouch-type lithium ion polymer battery is completed.

As the polymer contained in the composite membrane, any polymer that can protect the lithium anode can be used.

As a negative electrode active material for a negative electrode in a lithium sulfur secondary battery, a carbon material, which is a material capable of reversibly intercalating / deintercalating lithium ions, a material capable of reacting with lithium ions to reversibly form a lithium- Lithium alloy is used.

Any carbonaceous anode active material commonly used in lithium sulfur secondary batteries can be used as the carbonaceous material. Representative examples of the carbon material include crystalline carbon, amorphous carbon, or a combination thereof. Typical examples of the material capable of reacting with the lithium ion to form a lithium-containing compound reversibly include tin oxide (SnO ₂ ), titanium nitrate, silicon (Si), and the like, but are not limited thereto. As the lithium alloy, an alloy of lithium and a metal selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al and Sn can be used.

In the lithium sulfur secondary battery, elemental sulfur (S ₈ ), a sulfur element-containing compound, or a mixture thereof is used as the cathode active material of the anode, and Li ₂ S _n (n≥1) At least one selected from Li ₂ S _n ( _n ? 1), an organic sulfur compound, and a carbon-sulfur polymer ((C ₂ S _x ) _n : x = 2.5 to 50, n? 2) dissolved in a catholyte use.

A compound capable of reversibly intercalating and deintercalating lithium (a lithium intercalation compound) can be used as a positive electrode active material of a positive electrode in a lithium ion secondary battery. The positive electrode active material may include at least one selected from the group consisting of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, and lithium manganese oxide. However, May be used.

Wherein the cathode active material is lithium cobalt oxide of LiCoO ₂ ; Lithium nickel oxide LiNiO ₂ of the formula; Lithium manganese oxides such as Li _{1 + x} Mn _{2 - x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , or LiMnO ₂ ; Lithium copper oxide of the formula Li ₂ CuO ₂ ; Lithium iron oxide of the formula LiFe ₃ O ₄ ; Lithium vanadium oxide of the formula LiV3O8; Copper vanadium oxides of the formula Cu ₂ V ₂ O ₇ ; A vanadium oxide of the formula V ₂ O ₅ ; Formula LiNi _{1- x} M _x O ₂ (where, the M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, x = 0.01 ~ 0.3 Im), lithium nickel oxide; Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); A lithium manganese oxide in which a part of Li of the formula LiMn ₂ O ₄ is substituted with an alkaline earth metal ion; Disulfide compounds; And an iron molybdenum oxide of the formula Fe ₂ (MoO ₄ ) ₃ .

As the negative electrode active material, a carbon-based material, silicon, silicon oxide, a silicon-based alloy, a silicon-carbon-based material composite, tin, a tin alloy, a tin-carbon composite material, a metal oxide or a combination thereof may be used.

The carbon-based material includes carbon, graphite or carbon nanotubes.

Examples of the negative electrode active material in the negative electrode of the lithium ion secondary battery include those selected from the group consisting of Si, SiO _x (0 <x <2, for example, 0.5 to 1.5), Sn, SnO ₂ , Can be used. At least one of Al, Sn, Ag, Fe, Bi, Mg, Zn, in, Ge, Pb and Ti may be used as the metal capable of forming the silicon-containing metal alloy.

The negative electrode active material may include a metal / metalloid alloy that is alloyable with lithium, an alloy thereof, or an oxide thereof. For example, the lithium-alloyable metal / quasi-metal, the alloy thereof, or the oxide thereof may be at least one selected from the group consisting of Si, Sn, Al, Ge, Pb, Bi, SbSi-Y alloy (Y is an alkali metal, (Wherein Y is an alkali metal, an alkaline earth metal, a Group 13 element to a Group 16 element, a transition metal, a rare earth element, or an element selected from the group consisting of transition metals, rare earth elements or combinations thereof, Or a combination thereof, but not Sn), MnOx (0 < x? 2), and the like. The element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Se, Te, Po, or a combination thereof. For example, the oxide of the metal / metalloid capable of alloying with lithium may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO ₂ , SiO _x (0 <x <2) and the like.

For example, the negative electrode active material may include one or more elements selected from the group consisting of Group 13 elements, Group 14 elements, and Group 15 elements of the Periodic Table of the Elements.

For example, the negative electrode active material may include at least one element selected from the group consisting of Si, Ge, and Sn.

The negative electrode active material may be a composite of a carbon-based material and a selected one of silicon, silicon oxide, and silicon-containing metal alloy, or a composite of a carbon-based material and one selected from silicon, silicon oxide, and silicon-containing metal alloy.

For example, the shape of the negative electrode active material may be a simple particle shape or a nanostructure having a nano-sized shape. For example, the anode active material may have various shapes such as nanoparticles, nanowires, nano-rods, nanotubes, and nanobelt.

As the separator present in the positive electrode and the negative electrode, a mixed multilayer film such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, a polypropylene / polyethylene / polypropylene three- have.

The electrolyte used in the lithium secondary battery includes an organic solvent and a lithium salt.

Examples of the organic solvent include benzene, fluorobenzene, toluene, dimethylformamide, dimethylacetate, trifluorotoluene, xylene, cyclohexane, tetrahydrofuran, 2-methyltetrahydrofuran, cyclohexanone, ethanol, isopropyl alcohol , Dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl propionate, ethyl propionate, methyl acetate, ethyl acetate, propyl acetate, dimethoxyethane, 1,3-dioxolane, diglyme, tetra At least one solvent selected from the group consisting of glyme, ethylene carbonate, propylene carbonate,? -Butyrolactone and sulfolane can be used.

Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroazenate (LiAsF ₆ ), lithium perchlorate (LiClO ₄ ), lithium trifluoromethane sulfonate (LiSO ₃ CF _3), lithium-bis (trifluoromethyl) sulfone imide lithium bis (trifluoromethylsulfonyl) imide (LiN (SO ₂ CF _{3) 2),} lithium bis (perfluoroethyl sulfonyl) imide (LiN ( SO ₂ C ₂ F ₅ ) ₂ ) may be used.

In the electrolyte solution, the concentration of the lithium salt is, for example, 0.01 to 5 M, for example, 0.1 to 2.0 M.

The lithium secondary battery such as the lithium-sulfur secondary battery and the lithium ion secondary battery described above protects the lithium anode, thereby suppressing the side reaction between the lithium anode and the electrolyte, as well as improving the lithium ion conductivity, thereby improving the conductivity and lifetime.

The definitions of substituents used in the formulas described herein are as follows.

The term &quot; alkyl &quot; used in the formulas refers to fully saturated branched or unbranched (or linear or linear) hydrocarbons.

Non-limiting examples of the "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, isopentyl, neopentyl, , 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl and the like.

The "alkyl" at least one hydrogen atom of which is a halogen atom, a halogen atom, an alkyl group of the optionally substituted C1-C20: (for example CF _3, CHF _2, CH ₂ F, CCl _3, etc.), an alkoxy of C1-C20, C2-C20 A carboxyl group or a salt thereof, a sulfonyl group, a sulfamoyl group, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a phosphoric acid group or a salt thereof, C20 alkyl group, a C2-C20 alkenyl group, a C2-C20 alkynyl group, a C1-C20 heteroalkyl group, a C6-C20 aryl group, a C6-C20 arylalkyl group, a C6-C20 heteroaryl group, C20 heteroarylalkyl groups, C6-C20 heteroaryloxy groups, C7-C20 heteroaryloxyalkyl groups or C7-C20 heteroarylalkyl groups.

The term &quot; halogen atom &quot; includes fluorine, bromine, chlorine, iodine and the like.

The term "C1-C20 alkyl group substituted by a halogen atom" refers to a C1-C20 alkyl group substituted by at least one halo group, and includes, but is not limited to, a monohaloalkyl, dihaloalkyl or perhaloalkyl Or a polyhaloalkyl.

Monohaloalkyl refers to the case of having one iodine, bromine, chlorine or fluorine in the alkyl group, and dihaloalkyl and polyhaloalkyl represent alkyl groups having two or more same or different halo atoms.

The term &quot; alkoxy &quot; used in the formula represents alkyl-O-, and the alkyl is as described above. Non-limiting examples of the alkoxy include methoxy, ethoxy, propoxy, 2-propoxy, butoxy, tert-butoxy, pentyloxy, hexyloxy and the like. At least one hydrogen atom in the alkoxy group may be substituted with the same substituent as the alkyl group described above.

The term &quot; alkenyl &quot; group used in the formulas refers to branched or unbranched hydrocarbons having at least one carbon-carbon double bond. Non-limiting examples of the alkenyl group include vinyl, allyl, butenyl, propynyl, isobutenyl, etc., and at least one hydrogen atom of the alkenyl may be substituted with the same substituent as the alkyl group .

The term &quot; alkynyl &quot; group used in the formulas refers to branched or unbranched hydrocarbons having at least one carbon-carbon triple bond. Non-limiting examples of the "alkynyl" include ethynyl, butynyl, isobutynyl, propynyl, and the like.

At least one hydrogen atom of the above-mentioned &quot; alkynyl &quot; may be substituted with the same substituent as in the above-mentioned alkyl group.

The term &quot; aryl &quot; group used in the formulas, alone or in combination, means an aromatic hydrocarbon group containing at least one ring.

The term &quot; aryl &quot; also includes groups wherein an aromatic ring is fused to one or more cycloalkyl rings.

Non-limiting examples of the "aryl" include phenyl, naphthyl, tetrahydronaphthyl, and the like.

Also, at least one hydrogen atom in the above &quot; aryl &quot; group may be substituted with the same substituent as the above-mentioned alkyl group.

The term &quot; arylalkyl &quot; means alkyl substituted with aryl. As examples of aryl alkyl benzyl or phenyl, -CH ₂ CH ₂ - it may be mentioned.

The term &quot; aryloxy &quot; used in the formula means -O-aryl, and examples of the aryloxy group include phenoxy and the like. At least one hydrogen atom in the above-mentioned &quot; aryloxy &quot; group may be substituted with the same substituent as in the case of the above-mentioned alkyl group.

The term &quot; heteroaryl &quot; group used in the formulas means a monocyclic or bicyclic organic group containing one or more heteroatoms selected from N, O, P or S and the remaining ring atoms being carbon . The heteroaryl group may contain, for example, from 1 to 5 hetero atoms, and may include 5-10 ring members. The S or N may be oxidized to have various oxidation states.

At least one hydrogen atom of the above-mentioned &quot; heteroaryl &quot; can be substituted with the same substituent as in the case of the above-mentioned alkyl group.

The term &quot; heteroarylalkyl &quot; means alkyl substituted by heteroaryl.

The term &quot; heteroaryloxy &quot; means an-O-heteroaryl moiety. At least one hydrogen atom of the heteroaryloxy may be substituted with the same substituent as the alkyl group described above.

The &quot; carbon ring &quot; group used in the formula refers to a saturated or partially unsaturated non-aromatic monocyclic, bicyclic or tricyclic hydrocarbon group.

Examples of the monocyclic hydrocarbons include cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, and the like. Examples of bicyclic hydrocarbons include bornyl, decahydronaphthyl, bicyclo [2.1.1] hexyl, bicyclo [2.2. 1] heptyl, bicyclo [2.2.1] heptenyl, or bicyclo [2.2.2] octyl.

Examples of the tricyclic hydrocarbons include adamantly and the like.

At least one hydrogen atom of the above-mentioned &quot; carbon ring &quot; may be substituted with the same substituent as in the case of the above-mentioned alkyl group.

The &quot; heterocyclic &quot; group used in the formula refers to a cyclic group having 5 to 10 atoms containing hetero atoms such as nitrogen, sulfur, phosphorus, oxygen, etc. and specific examples thereof include pyridyl and the like. The atom is substitutable as in the case of the above-mentioned alkyl group.

The term &quot; sulfonyl &quot; means R &quot; -SO ₂ -, wherein R "is hydrogen, alkyl, aryl, heteroaryl, aryl-alkyl, heteroaryl-alkyl, alkoxy, aryloxy, cycloalkyl or heterocyclic group.

The term "sulfamoyl" group _{H 2 NS (O 2) -} , alkyl, -NHS (O ₂₎ -, _{(alkyl) 2 NS (O 2) -} , aryl-NHS (O ₂₎ -, alkyl (aryl) - NS (O ₂₎ -, (aryl) ₂ NS (O) _2, heteroaryl, -NHS (O ₂₎ -, _{(aryl-alkyl) - NHS (O 2) -} , or (heteroaryl-alkyl) -NHS ( O ₂ ) -.

At least one hydrogen atom of the sulfamoyl group is substitutable as in the case of the alkyl group described above.

The term &quot; amino group &quot; refers to the case where the nitrogen atom is covalently bonded to at least one carbon or heteroatom. The amino group includes, for example, -NH ₂ and substituted moieties. Alkylamino &quot; wherein the nitrogen atom is bonded to at least one additional alkyl group, &quot; arylamino &quot; and &quot; diarylamino &quot; in which at least one nitrogen or two or more are bonded to an independently selected aryl group.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example  One: Composite membrane  Produce

Lithium-titanium-aluminum-phosphate (LTAP: Li _1.4 Ti _1.6 Al _0.4 P ₃ O ₁₂ ) membrane (Ohara corporation) was pulverized and sieved with pore diameters of about 63 μm and 53 μm To obtain LTAP particles having a size (average particle size) of about 58 탆.

To the vial was added 200 mg of the LTAP particles, 20 ml of toluene and 50 mg of isobutyl (triethoxy) silane (IB), and the mixture was stirred at 25 ° C for about 7 hours.

The reaction product was filtered, filtered, washed with acetone, and vacuum-dried at 60 DEG C for about 2 hours. The resultant vacuum-dried product was subjected to sieving with 53 μm and 63 μm mesh sieves to obtain LTAP (IB-LTAP) particles having a hydrophobic coating film of a condensation reaction product of IB having a size (average particle diameter) of about 58 μm .

Separately, 160 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 1,3,5-triallyl-1,3,5-triazine-2,4 , 240 mg of 1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) And 30 mg of Irgacure 369 (BASF) represented by the following formula, which is a photoinitiator, was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

Irgacure 369 (BASF)

The composition for forming a polymer membrane obtained as described above was dropped on a water surface of a petri dish (? = 3.2 cm) filled with water.

The petri dish lid was opened only one tenth and the ethanol and chloroform were slowly evaporated over 1 hour and the surface of the remaining monomer mixture was allowed to flatten.

The IB-LTAP particles were dried at 60 DEG C for about 30 minutes, and the moisture content contained therein was controlled to 100 ppm or less. 10 mg of IB-LTAP particles with moisture content controlled therein were spread on the planarized resultant.

The surface of the water was irradiated with UV for about 15 minutes using a low pressure mercury lamp (0.08 W / cm ² ), and TTT and 4T polymerization were carried out to obtain a composite membrane. The tweezers were used to separate the composite membrane from the water surface. Wherein the composite membrane has a polymer membrane having a plurality of through holes and a LTAP particle formed on the through hole, wherein a hydrophobic coating film composed of a condensation reaction product of IB is formed on the LTAP particle surface. The content of the condensation reaction product of IB was about 0.01 parts by weight based on 100 parts by weight of the LTAP particles. The content of the LTAP particles having the hydrophobic coating layer formed was 100 parts by weight of the total weight of the composite membrane Based on 43 parts by weight. The average thickness of the composite membrane was 70 mu m.

Example  2: Composite membrane  Produce

200 mg of the IB-LTAP particles obtained in Example 1, 20 mg of toluene and 50 mg of 3-methacrylpropyltrimethoxysilane (PM) were stirred for about 30 minutes to obtain a reaction mixture. After the reaction mixture was filtered The product obtained by filtration was washed with acetone.

IB-LTAP (IB-LTAP) particles modified by IB were subjected to vacuum drying at 60 ° C for about 2 hours, and then subjected to a sieving with a pore diameter of about 53 탆 and 63 탆 for the obtained product. .

Separately, 160 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 1,3,5-triallyl-1,3,5-triazine-2,4 , 240 mg of 1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) And 30 mg of Irgacure 369 (BASF) represented by the following formula, which is a photoinitiator, was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

Irgacure 369 (BASF)

The composition for forming a polymer membrane obtained as described above was dropped on a water surface of a petri dish (? = 3.2 cm) filled with water.

The petri dish lid was opened only one tenth and the ethanol and chloroform were slowly evaporated over 1 hour and the surface of the remaining monomer mixture was allowed to flatten.

PM-IB-LTAP particles were dried at 60 DEG C for about 30 minutes, and the water content contained therein was controlled to be 100 ppm or less. 10 mg of PM-IB-LTAP particles with controlled moisture content were spread on the planarized product.

The surface of the water was irradiated with a low pressure mercury lamp (0.08 W / cm ² ) for about 15 minutes to photopolymerize TTT and 4T to obtain a composite membrane. The tweezers were used to separate the composite membrane from the water surface. The photopolymerization of TTT and 4T also involved photopolymerization of PM.

The composite membrane prepared according to the above process had a structure in which a polymer membrane having a plurality of through holes and LTAP particles formed in the through holes were formed, and a hydrophobic coating film composed of a condensation reaction product of IB and PM was formed on the LTAP particle surface. The content of the condensation reaction product of IB and PM was about 0.01 part by weight based on 100 parts by weight of the LTAP particles, and the content of the LTAP particles formed with the hydrophobic coating layer was about 100 parts by weight Was 43 parts by weight based on parts by weight. The average thickness of the composite membrane was 70 mu m.

Example  3: Composite membrane  Produce

Crystal phases of lithium-titanium-aluminum-phosphate _{(... LTAP: Li 1} 4 Ti 1 6 Al 0 4 P 3 O 12) to which _{Li 2 O, Al 2 O3,} SiO 2, P 2 O 5, TiO 2 and GeO the lithium ion conductivity comprised of _two ceramic plates (Ohara glass) (Ohara corporation) ( thickness: about ^{260㎛, 3.05mg / cm 3, 88} mg / cm 2) and the crushing them pore diameter 53-63㎛, 75 the -90 占 퐉 and 100-125 占 퐉 mesh were sieved to obtain LTAP particles each having a size (average particle size) of about 58, 83, and 113 占 퐉, respectively.

To the vial was added 200 mg of the LTAP particles, 20 ml of toluene and 50 mg of isobutyl (triethoxy) silane (IB), and the mixture was stirred at 25 ° C for about 7 hours.

The reaction product was filtered, filtered, washed with acetone, and vacuum-dried at 60 DEG C for about 2 hours. Subsequently, a vacuum-dried product was subjected to sieving with a pore diameter of about 75-90 μm to obtain a hydrophobic coating film of a condensation reaction product of IB having sizes (average particle size) of about 58, 83, and 113 μm, respectively To form LTAP (IB-LTAP) particles formed.

200 mg of the LTAP particles (IB-LTAP particles), 20 mg of toluene and 50 mg of 3-methacrylpropyltrimethoxysilane (PM) were stirred for about 30 minutes. After filtration of the reaction mixture, And washed with acetone.

The resultant product was vacuum dried at 60 DEG C for about 2 hours and sieved with a pore diameter of about 53 to 63 mu m, 75 to 90 mu m, and 100 to 125 mu m for the obtained product, IB-LTAP (PM-IB-LTAP) particles.

On the surface of the PM-IB-LTAP particles, a hydrophobic coating film modified by hydrophobic IB and polar PM was formed and a uniform layer of PM-IB-LTAP particles was formed without pinholes.

Separately, 500 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 500 mg of 1,3,5-triallyl-1,3,5-triazine-2,4 , 330 mg of 1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) And 30 mg of Irgacure 369 (BASF) as a photoinitiator was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

0.46 ml of the composition for forming a polymer membrane obtained by the above procedure was added dropwise to the water surface of a petri dish (? = 3.2 cm) filled with water. The monomer solution was floated in water, covered with a lid of 90%, and then slowly evaporated for 1 hour to evaporate the ethanol and the chloroform to flatten the surface of the remaining monomer mixture.

The ion conductive particle PM-IB-LTAP was dried at 60 占 폚 for 30 minutes. The water content at that time was controlled to be 100 ppm or less. 10 mg of PM-IB-LTAP particles with controlled moisture content were spread on the planarized product.

UV light was irradiated onto the water surface using a UV cross-linker CL-100 (254 nm, 10 mW / cm ² ) for about 15 minutes to photopolymerize TTT and 4T to obtain a composite membrane. The tweezers were used to separate the composite membrane from the water surface. The photopolymerization of TTT and 4T also involved photopolymerization of PM.

The composite membrane obtained by the above process has a structure in which a polymer membrane having a plurality of through holes and LTAP particles formed in the through holes are formed, and a hydrophobic coating film composed of a condensation reaction product of IB and PM is formed on the LTAP particle surface. The content of the condensation reaction product of IB and PM was about 0.01 part by weight based on 100 parts by weight of the LTAP particles, and the content of the LTAP particles formed with the hydrophobic coating layer was about 100 parts by weight Was 43 parts by weight based on parts by weight. The average thickness of the composite membrane was 60 占 퐉, respectively.

Comparative Example  One: LTAP membrane  Produce

A LTAP film (Ohara glass) having a thickness of about 260 μm was used.

Comparative Example  2: TTT - 4T membrane  Produce

500 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 500 mg of 1,3,5-triallyl-1,3,5-triazine-2,4,6 330 mg of 1,3,5-triazine-1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) A mixture was obtained. 30 mg of Irgacure 369 (BASF) as a photoinitiator was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

The composition for forming a polymer membrane obtained above was cast in a Petri dish (Ф = 3.2 cm), UV was irradiated with UV light using a UV cross-linker CL-100 (254 nm, 10 mW / cm ² ) Min for photopolymerization of TTT and 4T to obtain a TTT-4T film

Example  4: Lithium Air Battery  Produce

First, a DEME-TFSI (N, N-diethyl-N-methyl-N-methyl-N, N-diethylaminoethyl) diphenylmethane diisocyanate (DMEM) containing multi- walled carbon nanotubes (XinNano) and 1M lithium bis (trifluorosulfonylimide) (2-methoxyethyl) ammonium bis (trifluoromethylsulfonyl) imide) and polyvinylidene fluoride in a weight ratio of 5: 25: 1 to prepare a sheet-like cathode. The sheet-form cathode was cut to obtain a cathode in the form of a disk having a diameter of 8 mm.

A disc of lithium metal (thickness: 500 mu m) having a diameter of about 15 mm was used as an anode.

2 g of polyethylene oxide, 0.31 g of silica gel and 0.26 g of LiTFSI were dissolved in 50 ml of acetonitrile and mixed for 7 hours to obtain a polymer solution. This polymer solution was cast in a Teflon dish and dried to obtain a polymer electrolyte film having a thickness of about 190 탆.

The polymer film was punched to obtain a polymer electrolyte disk having a diameter of about 15 mm. A copper thin film, a lithium metal disk, a polymer electrolyte disk, a composite membrane of Example 3, a cathode, and a gas diffusion layer 35BA (SGL group) were assembled to prepare a lithium air battery.

Example  5-6: Lithium Air Battery  Produce

A lithium air cell was produced in the same manner as in Example 4, except that the composite membrane of Examples 1 and 2 was used instead of the composite membrane of Example 3, respectively.

Example  7: Composite membrane  Produce

A composite membrane was prepared in the same manner as in Example 3, except that trimethylolpropane triacrylate was used instead of TTT in the preparation of the composition for forming a polymer membrane.

Example  8: Lithium Air Battery  Produce

A lithium air cell was produced in the same manner as in Example 4 except that the composite membrane of Example 7 was used in place of the composite membrane of Example 3, respectively.

Example  9: Composite membrane  Produce

Crystal phases of lithium-titanium-aluminum-phosphate _{(... LTAP: Li 1} 4 Ti 1 6 Al 0 4 P 3 O 12) to which _{Li 2 O, Al 2 O3,} SiO 2, P 2 O 5, TiO 2 and GeO the lithium ion conductivity comprised of _two ceramic plates (Ohara glass) (Ohara corporation) ( thickness: about ^{260㎛, 3.05mg / cm 3, 88} mg / cm 2) and grinding the body this pore diameter of about 75 to the network 90㎛ , And sieving was performed to obtain LTAP particles each having a size (average particle diameter) of about 83 탆.

200 mg of the LTAP particles, 20 ml of toluene and 50 mg of (3-mercaptopropyl) trimethoxysilane (SH) were added to the vial and the mixture was stirred at 25 ° C for about 7 hours.

The reaction product was filtered, filtered, washed with acetone, and vacuum-dried at 60 DEG C for about 2 hours. Subsequently, the pore diameter of the resultant vacuum-dried product was sieved to about 100-125 μm to form a hydrophobic coating film of a condensation reaction product of SH having a size (average particle size) of about 113 μm. The LTAP (SH- LTAP) particles were obtained.

50 mg of 1H-1H, 2H, 2H-perfluorooctyltriethoxy silane (PFO) was dissolved in 200 mg of the above LTAP particles (SH-LTAP particles), 20 mg of toluene and 50 mg of 1H, 1H, 2H, 2H-perfluorooctyltriethoxy silane Lt; / RTI &gt; The reaction mixture was filtered, filtered and washed with acetone.

The resultant product was vacuum-dried at 60 ° C. for about 2 hours and sieved with a pore diameter of about 100-125 μm to obtain PFO-modified SH-LTAP (PFO-SH-LTAP ) Particles.

On the surface of the PFO-SH-LTAP particles, PFO and SH modified hydrophobic coatings were formed, forming a uniform layer of PFO-SH-LTAP particles without pinholes.

Separately, 500 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 500 mg of 1,3,5-triallyl-1,3,5-triazine-2,4 , 330 mg of 1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) And 30 mg of Irgacure 369 (BASF) as a photoinitiator was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

0.46 ml of the composition for forming a polymer membrane obtained by the above procedure was added dropwise to the water surface of a petri dish (? = 3.2 cm) filled with water. The monomer solution was floated in water, covered with a lid of 90%, and then slowly evaporated for 1 hour to evaporate the ethanol and the chloroform to flatten the surface of the remaining monomer mixture.

The ion conductive particle PM-IB-LTAP was dried at 60 占 폚 for 30 minutes. The water content at that time was controlled to be 100 ppm or less. 10 mg of PM-IB-LTAP particles with controlled moisture content were spread on the planarized product.

The water surface was irradiated with UV Crosslinker CL-100 (254 nm, 10 mW / cm ² ) for about 15 minutes to photopolymerize TTT and 4T to obtain a composite membrane. The tweezers were used to separate the composite membrane from the water surface. The photopolymerization of TTT and 4T also involved photopolymerization of PM.

The composite membrane obtained according to the above process has a structure in which a polymer membrane having a plurality of through holes and LTAP particles formed in the through holes are formed, and a hydrophobic coating film composed of a condensation reaction product of PFO and SH is formed on the LTAP particle surface. The content of the condensation reaction product of PFO and SH was about 0.01 parts by weight based on 100 parts by weight of the LTAP particles, and the content of the LTAP particles formed with the hydrophobic coating layer was about 100 parts by weight Was 43 parts by weight based on parts by weight. The average thickness of the composite membrane was 70 mu m.

Example  10: Composite membrane  Produce

Except that trimethoxy (3,3,3-trifluoropropyl) silane (TF) was used instead of PFO in place of PFO To prepare a composite membrane.

Example  11: Composite membrane  Produce

Except that PM was used in place of (3-mercaptopropyl) trimethoxysilane (SH) in Example 9 to obtain a composite membrane.

Example  12: Composite membrane  Produce

Except that trimethoxy (3,3,3-trifluoropropyl) silane (TF) was used instead of PFO in place of PFO To prepare a composite membrane.

Comparative Example  3: Lithium Air Battery  Produce

A lithium air cell was produced in the same manner as in Example 4 except that the LTAP membrane of Comparative Example 1 was used instead of the composite membrane of Example 3.

Comparative Example  4

200 mg of LTAP particles, 20 mg of toluene and 50 mg of 3-methacrylpropyltrimethoxysilane (PM) were stirred for about 15 minutes. After filtration of the reaction mixture, the resulting product was filtered and washed with acetone.

The resultant product was vacuum dried at 60 ° C for about 2 hours, and then subjected to 63 μm sieving to obtain a PM hydrophobic coating film to obtain PM-LTAP particles modified with PM.

Separately, 160 mg of pentaerythritol tetrakis (3-mercaptopropionate: 4T) and 1,3,5-triallyl-1,3,5-triazine-2,4 , 240 mg of 1,3,5-triazine-2,4,6-trione (TTT) was dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) And 30 mg of Irgacure 369 (BASF) represented by the following formula, which is a photoinitiator, was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

Irgacure 369 (BASF)

The composition for forming a polymer membrane obtained as described above was dropped on a water surface of a petri dish (? = 3.2 cm) filled with water.

The petri dish lid was opened only one tenth and the ethanol and chloroform were slowly evaporated over 1 hour and the surface of the remaining monomer mixture was allowed to flatten.

The PM-LTAP particles were dried at 60 DEG C for about 30 minutes and the water content contained therein was controlled to be 100 ppm or less. 10 mg of PM-IB-LTAP particles with controlled moisture content were spread on the planarized product.

The surface of the water was irradiated with a low pressure mercury lamp (0.08 W / cm ² ) for about 15 minutes to photopolymerize TTT and 4T to obtain a composite membrane. The tweezers were used to separate the composite membrane from the water surface. The photopolymerization of TTT and 4T also involved photopolymerization of PM.

The composite membrane manufactured according to the above process had a structure in which a polymer membrane having a plurality of through holes and LTAP particles formed in the through holes were formed, and a hydrophobic coating film composed of PM condensation reaction product was formed on the surface of the LTAP particles. The content of the condensation reaction product of PM was about 0.01 parts by weight based on 100 parts by weight of the LTAP particles. The content of the LTAP particles formed with the hydrophobic coating layer was 100 parts by weight of the total weight of the composite membrane. The hydrophobic coating layer had a thickness of about 10 nm or less, Based on 43 parts by weight. The average thickness of the composite membrane was 70 mu m.

Comparative Example  5-7

PFO (1H, 1H, 2H, 2H-perfluorooctyltriethoxy silane), n-decyltriethoxysilane (D) and (3-mercaptopropyl) trimethoxysilane trimethoxysilane SH), respectively, were used in place of the polyimide precursor, to prepare a composite membrane.

Comparative Example  8: LTAP membrane

An LTAP film (Ohara glass) having a thickness of 70 mu m instead of about 260 mu m was used.

Evaluation example  One: Contact angle

The contact angles of the composite membrane prepared according to Examples 1 to 3, 9 to 12 and the LTAP membrane of Comparative Example 1-8 were measured. The contact angle was measured using a drop shape analyzer DSA100S (Kruss), which is a contact angle measuring instrument, and the contact angle was measured as follows.

First, the contact angle of the LATP membrane of Comparative Example 1 was measured by dropping droplets of water on the surface of the membrane, and then measuring the angle between the water droplet and the LTAP membrane.

The contact angle for the composite membrane prepared according to Example 3 was measured according to the following method.

The contact angle a / w / p (? Awp) of the PM-IB-LTAP particles was determined by adding the PM-IB-LTAP particles obtained in Example 3 to the water surface of a petri dish (? = 3.2 cm) Were measured. Where a, w and p denote air, water and particles, respectively.

Separately, 500 mg of monomer 4T and 330 mg of TTT were dissolved in 6.6 ml of a mixed solvent of ethanol and chloroform (1: 1 mixed volume ratio) to obtain a mixture. 30 mg of Irgacure 369 (BASF) as a photoinitiator was added to this mixture, followed by stirring to obtain a composition for forming a polymer membrane.

0.46 ml of the composition for forming a polymer membrane obtained by the above procedure was added dropwise to the water surface of a petri dish (Ф = 3.2 cm) filled with water.

The contact angle a / m / p (? Amp) of the PM-IB-LTAP particles and the contact angle w / m / p (? Wmp) were measured 30 minutes after the dropping. a, m, p, and w are abbreviations of air, monomer, particle, and water, respectively.

The contact angle a / w / p (? Awp), the contact angle a / m / p (? Amp) and the contact angle w / m / p (? Wmp) in the composite membrane according to Examples 1 and 2 were the LTAP particles IB LTAP particles obtained in Example 2 and PM-IB-LTAP particles obtained in Example 2 were used instead of the particles of the IB-LTAP particles obtained in Example 1 and the particles of the PM-IB-LTAP particles obtained in Example 2, respectively .

The measurement results of the contact angle a / w / p (? Awp), the contact angle a / m / p (? Amp) and the contact angle w / m / p (? Wmp) are shown in Table 1 below.

division Composition of composite membrane Θawp (°) Θamp (°) Θ wmp (°) Example 1
Thickness: about 70 mu m) IB-LTAP / TTT + 4T - 58.2 (62.1) 75.4 (81.2) Example 2
Thickness: about 70 mu m) PM-IB-LTAP / TTT + 4T - 43.6 80.3 Example 3
(Thickness: about 30 mu m) PM-IB-LTAP / TTT + 4T 66.2 43.6 80.3 Example 9 (thickness: about 70 mu m) PFO-SH-LTAP / TTT + 4T - 32.7 (36.9) 64.0 (65.1) Example 10
(Thickness: about 70 mu m) TF-SH-LTAP / TTT + 4T - 33.1 (40.5) 82.9 (87.9) Example 11
(Thickness: about 70 mu m) PFO-PM-LTAP / TTT + 4T - 34.4 72.5 Example 12
(Thickness: about 70 mu m) TF-PM-LTAP / TTT + 4T - 31.8 72.6 Comparative Example 1
(Thickness: about 260 탆) LTAP 42.8 41.3 110.0 Comparative Example 4
(Thickness: about 70 mu m) PM-LTAP / TTT + 4T - 28.7 92.3 Comparative Example 5
(Thickness: about 70 mu m) PFO-LTAP / TTT + 4T - 65.3 95.6 Comparative Example 6
(Thickness: about 70 mu m) D-LTAP / TTT + 4T - 24.8 62.1 Comparative Example 7
(Thickness: about 70 mu m) SH-LTAP / TTT + 4T - 29.7 112.6 Comparative Example 8
(Thickness: about 70 mu m) LTAP 42.8 41.3 110.0

In Examples 1, 9, and 10 in Table 1, numerical values in parentheses of numerical values of Θamp and Θwmp indicate contact angles measured in a composite film state.

As shown in Table 1, the composite membranes prepared according to Examples 1 to 3 and 9-12 had a contact angle a / w / p (? Awp), a contact angle a / m / p (? Amp) &amp;thetas; wmp) are all in the range of 30 to 90 DEG. This composite membrane showed a structure in which the particles were uniformly dispersed in the organic film without pinhole formation.

On the other hand, it was found that the composite membrane produced according to Comparative Example 1 had? Wmp exceeding 90 degrees. And the composite membranes prepared according to Comparative Examples 3 to 8 had a result that at least one of? Amp and? Wmp was out of the range of 30 to 90 degrees.

Evaluation example  2: Optical microscope analysis

Optical microscope analysis of the composite membrane (thickness: about 69 mu m) prepared according to Example 3 was performed. For the optical microscope, Nikon's Eclipse LV100D was used.

Optical microscope photographs of the composite membrane prepared according to Example 3 are shown in Figs. 7a to 7c. FIGS. 7A, 7B and 7C respectively show a cross section view, a top view and a bottom view of the composite membrane, respectively.

Referring to this, it can be seen that the composite membrane prepared according to Example 3 exists in a state where the polymer and the LTAP particles are uniformly dispersed. It was also found that the LTAP particles embedded in the polymer membrane were arranged in a monolayer structure.

Evaluation example  3: Resistance and impedance measurement

The composite membrane prepared according to Example 3 was prepared to have the tp and Xp ranges shown in Table 2 below, and a structure was prepared by sputtering platinum on the composite membrane. The impedance for this structure was measured.

division t _p (탆) Xp Composite membrane A 260 1.0 Composite membrane B 69 0.3 Composite membrane C 64 0.32 Composite membrane D 45 0.36

In Table 2, tp represents the thickness of the LTAP particles and Xp represents the area fraction of the LTAP particles in the composite membrane. Xp represents the ratio (Xp = Ap / A _total ) of the _total area A _total of the composite membrane to the total area Ap of the exposed LTAP particles as shown in the following Equation 11, as shown in FIG. 8d.

[Equation 11]

Xp = Ap / A _total

In Equation 11, Ap is the total area of the exposed particles and A _total is the _total area of the composite membrane.

The impedance measuring instrument was an impedance analyzer VMP3 from Bio Logic. The impedance of the structure was maintained at about 20, 40, 60, 80, and 100 ° C, respectively, and the results of the impedance analysis according to the temperature are shown in FIG. In FIG. 8A, Z represents the real impedance (? Cm ² ) and Z "represents the imaginary impedance (? Cm ² ).

The impedance is a profile as a function of the impedance of the real and imaginary parts evaluated under the condition of applying an AC voltage of about 5 mV in a frequency range from 1 Hz to 100 MHz.

With reference to, the embodiment of the composite a structure employing a film 3 is from about 60 ℃ 3.9 × 10 ^-4 Scm ^- was found to have excellent impedance characteristics in the ion conductor ¹ exhibited excellent properties in especially below 60 ℃.

Also, the area resistivity was evaluated according to the temperature while varying the total area (Ap) of the PM-IB-LTAP particles exposed on the upper part of the composite membranes A to D prepared according to Example 3 above. The area specific resistivity was calculated from the impedance characteristics.

FIG. 8B shows the change in the conductivity according to the occupied area of the LTAP particles as the ion conductive inorganic particles in the composite membranes A to D, and FIG. 8C shows the area specific resistance according to the temperature change.

The conductivity of the LTAP particles is as shown in Equation 12 below.

[Equation 12]

σ _p = t _p / A _p R

In formula 12, R represents an area specific resistance. And t _p and A _p denote the thickness and the partial area of the exposed PM-IB-LTAP particle, respectively, and t _p / A _p is a shape parameter.

The area resistivity evaluation result is shown in Fig. 8C.

Referring to FIG. 8B, the correlation between the thickness, the occupied area and the conductivity of the ion conductive inorganic particles was found.

Referring to Fig. 8C, the composite membrane D has the smallest thickness of the LTAP particles as compared with the composite membranes A to C. The area specific resistance of the composite film D was found to be about 29? Cm ² , which was smaller than the area specific resistance (66? Cm ²⁾ of the LTAP electrode plate (Xp = 1, tp = 200 占 퐉). From this it can be seen that the channel structure of the composite membrane according to one embodiment significantly reduces the area specific resistance and area weight.

Evaluation example  4: Oxygen permeability analysis

1) Examples 1-2 and Comparative Examples 1-8

The oxygen permeabilities of the composite membrane prepared according to Examples 1 and 2 and the LTAP membrane prepared according to Comparative Examples 1 to 8 were evaluated according to the following methods.

OX-TRAN 2/21 ML of MOCON was used as an Oxygen Transmission Rate Tester, and an oxygen permeation experiment was performed with a sample disc having an area of about 1 cm ² .

The evaluation results of the oxygen permeability are shown in Table 3 below.

division Oxygen permeability (cm ³ cm / m ² day atm) Example 1 0.52 Example 2 0.31 Comparative Example 1 0.21 Comparative Example 2 0.70 Comparative Example 4 Measurement unavailable (> 100000) Comparative Example 5 Measurement unavailable (> 100000) Comparative Example 6 Measurement unavailable (> 100000) Comparative Example 7 Measurement unavailable (> 100000) Comparative Example 8 Measurement unavailable (> 100000)

As shown in Table 3, the composite membrane prepared according to Example 1-2 exhibited excellent oxygen blocking properties.

On the other hand, in Comparative Examples 1 and 2, the oxygen permeability was lower than that in Examples 1 and 2, and the composite membranes of Comparative Examples 3 to 8 exceeded the measurement limit for oxygen permeability.

2) Examples 2 and 3, Comparative Example 1 and Comparative Example 2

The oxygen permeability and the moisture permeability of the composite membrane prepared according to Examples 2 and 3, the LTAP membrane prepared according to Comparative Example 1 and the TTT-4T membrane prepared according to Comparative Example 2 were measured by the following method Respectively.

Oxygen and water permeability were measured using a continuous flow test method according to ASTM (D3985) using MOCON Aquatran model 1 and MOCON Oxytran 2/21 instruments, respectively (MOCON).

The sample disk was flushed with nitrogen gas at an area of about 1 cm ² , and the excess gas was purged to conduct oxygen and water permeation test. The evaluation results are shown in FIG. 9 and Table 4 below.

division Water permeability (cm ³ cm / m ² day atm) Oxygen permeability (cm ³ cm / m ² day atm) Example 2 237 0.31 Example 3 623 0.41 Comparative Example 1 0.03 0.21 Comparative Example 2 810.4 0.70

9 and Table 4, it was found that the oxygen permeability and the water permeability of the composite membrane prepared according to Examples 2 and 3 were improved as compared with the TTT-4T membrane prepared according to Comparative Example 2. Therefore, it was found that the composite membrane produced according to Example 3 had excellent oxygen and moisture barrier properties. Thus, the oxygen permeability and water permeability of the composite membrane prepared according to Example 3 are improved by the absence of a leak between the two components of the TTT-4T polymer matrix and PM-IB-LTAP particles This is because the blocking effect is excellent.

Evaluation example  5: Lithium Air Battery Charging and discharging  Characteristics and Cycle Characteristics

The lithium air cell produced according to Example 4 was placed in a chamber where the temperature was maintained at about 60 DEG C under an oxygen atmosphere. The cell was charged with a constant current mode of 0.24 mA / cm &lt; ² &gt; at 1 atm of oxygen and charged in a constant voltage mode of 4.3V.

The charge-discharge capacity of the lithium air battery was fixed at about 200 mAh / g _carbon .

The charge-discharge characteristics of the lithium air battery are shown in FIG. 10, and the cycle characteristics are shown in FIG.

Referring to FIG. 10, the charge / discharge characteristics of the lithium air battery showed a discharge plateau at about 2.6V.

Referring to FIG. 11, it can be seen that the lithium ion air cell has a reduced discharge capacity after about 93 cycles. This discharge capacity reduction furnace is caused by cathode deterioration occurring in the lithium air cell.

Evaluation example  6: XPS  analysis

PM-IB-LTAP particles prepared according to Example 3 were analyzed using XPS. The analysis results of Si 2p and C 1s of XPS are shown in FIGS. 12a and 12b.

Referring to this, C1S peaks appear at 284.7 eV and 288.6 eV, which are due to C-H and C = O corresponding to IB and PM. From these results, it was found that the LTAP particles obtained according to Example 3 had a hydrophobic coating film modified with IB-PM.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the appended claims. will be.

10, 22: composite membrane 11, 21: ion conductive inorganic particle
12, 22: Polymer membrane 13: Through hole

Claims (34)

A composite film comprising an organic film having a plurality of through holes and a plurality of ion conductive inorganic particles disposed in the through holes,
Wherein the composite membrane or the plurality of ion conductive inorganic particles have a contact angle of 30 to 90 DEG. The method according to claim 1,
Wherein the composite membrane or the plurality of ion conductive inorganic particles have a contact angle of 40 to 85 占. The method according to claim 1,
Wherein the hydrophobic coating film is disposed on at least one surface of the plurality of ion conductive inorganic particles. The method of claim 3,
Wherein the hydrophobic coating film is disposed on one surface of the plurality of ion conductive inorganic particles not exposed on the surface of the composite membrane. The method according to claim 1,
The surface of the composite membrane includes a sea-island structure in which ion conductive inorganic particles are discontinuously disposed in a continuous organic film, or
Wherein the cross section of the composite membrane comprises an alternately aligned structure of an organic film and an ion conductive inorganic material particle. The method according to claim 1,
Wherein the plurality of ion conductive inorganic particles embedded in the organic film are arranged in a monolayer. The method according to claim 1,
Wherein the organic film is a polymer membrane including at least one selected from a homopolymer, a block copolymer and a random copolymer. The method of claim 3,
Wherein the hydrophobic coating film comprises at least one condensation reaction product selected from a compound represented by the following formula (1): &lt; EMI ID =
[Chemical Formula 1]

In the above formula (1), R ₁ to R ₃ independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenyl group, Substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C2-C20 alkynyl groups, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C7- Or a substituted or unsubstituted C2-C20 heteroaryl group, a substituted or unsubstituted C2-C20 heteroaryloxy group, a substituted or unsubstituted C3-C20 heteroarylalkyl group, a substituted or unsubstituted C2-C20 heterocyclic group Or a halogen atom,
R ₄ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group or a substituted or unsubstituted C6-C20 aryl group. 9. The method of claim 8,
Wherein the compound represented by Formula 1 is selected from the group consisting of isobutyltrimethoxysilane, octyltrimethoxysilane, propyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, 3- Perfluorooctyltriethoxysilane, and (3-mercaptopropyl) trimethoxysilane. The silane coupling agent is selected from the group consisting of n-octyltrimethoxysilane, n-hexyltrimethoxysilane, At least one composite membrane. 9. The method of claim 8,
Wherein the content of the at least one condensation reaction product selected from the compounds represented by the formula (1) is 0.1 to 30 parts by weight based on 100 parts by weight of the plurality of ion conductive inorganic particles. The method according to claim 1,
Wherein the plurality of ion conductive inorganic particles are a single particle having no intergranular boundary. The method according to claim 1,
Wherein the content of the plurality of ion conductive inorganic particles is from 10 to 90 parts by weight based on 100 parts by weight of the total weight of the composite membrane. The method according to claim 1,
Wherein the plurality of ion conductive inorganic particles are at least one selected from a glassy active metal ion conductor, an amorphous active metal ion conductor, a ceramic active metal ion conductor, and a glass-ceramic active metal ion conductor, A composite membrane which is a combination of these. The method according to claim 1,
Wherein the plurality of ion conductive inorganic particles are Li _{1 + x + y} Al _x Ti _{2 - x} Si _y P _{3 - y} O ₁₂ (0 <x <2, 0≤y <3), BaTiO 3, Pb (Zr, Ti) O 3 (PZT), Pb 1 - x La x Zr 1 - y Ti y O 3 (PLZT) (O≤x <1, O≤y <1), Pb (Mg 3 Nb 2/3) O 3 -PbTiO 3 (PMN-PT), HfO 2, SrTiO 3, SnO 2, CeO 2, Na 2 O, MgO, NiO, _{CaO, BaO, ZnO, ZrO 2} , Y 2 O 3, Al 2 O 3, TiO 2, SiO 2, SiC, lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(Li x Ti y (PO 4} ) 3, 0 <x <2,0 <y < 3), lithium aluminum titanium phosphate _{(Li x Al y Ti z (} PO 4) 3, 0 <x <2, 0 <y <1, 0 <z <3), Li _{1 + x + y (Al,} Ga) x (Ti, Ge) 2 - x Si y P 3 - y O 12 (O≤x≤1, O≤y≤1), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (LixGeyPzSw, 0 <x <4, 0 <y <1, 0 <z < (Li _x N _y , 0 <x <4, 0 <y <2), SiS ₂ (Li _x Si _y S _z , 0 <x < P ₂ S ₅ series glasses (Li _x P _y S _z , 0 <x <3, 0 <y <3, 0 <z <7), Li ₂ O, LiF, LiOH, Li ₂ CO ₃ , LiAlO ₂ , Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ ceramics, Garnet ceramics Li _{3 + x} La ₃ M ₂ O ₁₂ (M = Te, Nb, or Zr) (x is an integer from 1 to 10), or a combination thereof. The method according to claim 1,
Wherein the organic film contains a polymer having moisture barrier and gas barrier properties. The method according to claim 1,
Wherein the organic film comprises a polymerization product of a polymerizable non-aqueous floating compound or a polymerization product of a polymerizable non-aqueous floating compound and a polythiol having three or four thiol groups. The method according to claim 1,
Wherein the organic film comprises i) a polymerized product of at least one polyfunctional monomer selected from polyfunctional acrylic monomers and polyfunctional vinyl monomers, or
ii) a composite membrane comprising a polymerization product of a polythiol having three or four thiol groups and at least one polyfunctional monomer selected from polyfunctional acrylic monomers and polyfunctional vinyl monomers. 18. The method of claim 17,
Wherein the polyfunctional monomer is selected from the group consisting of diurethane dimethacrylate, trimethylolpropane triacrylate, diurethane diacrylate, trimethylolpropane trimethacrylate, neopentyl glycol diacrylate, 3 Acryloxy-2 ', 2'-dimethylpropyl 3-acryloxy-2,2-dimethylpropionate), 3'-acryloxy- Bisphenol A acrylate and 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione (1,3,5-triallyl-1,3, 5-triazine-2,4,6-trione)
3-mercaptopropionate}, trimethylolpropane tris (3-mercaptopropionate)}, trimethylolpropane tris (3-mercaptopropionate) , 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol and pentaerythritol tetrakis (2-mercaptoacetate ) (Pentaerythritol Tetrakis (2-mercaptoacetate)), trimethylolpropane tris (2-mercaptoacetate). The method according to claim 1,
Wherein the organic film comprises a polymerization product of pentaerythritol tetrakis (3-mercaptopropionate) and 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione Composite membrane. The method according to claim 1,
Wherein the ion conductive inorganic particles have an average particle diameter of 1 to 300 占 퐉. The method according to claim 1,
Wherein the composite membrane has a gas permeability of 10 ^-3 to 1,000 cm ³ / m ² day atm,
Wherein the composite membrane has an exposed area of a plurality of ion conductive inorganic particles in an amount of 30 to 80% based on the total membrane area of the composite membrane. The method of claim 3,
Wherein the hydrophobic coating film has a thickness of 1 to 100 nm. The method according to claim 1,
Wherein a ratio (Xp = Ap / A _total ) of the total surface area (A _total ) of the composite membrane to a total surface area of a plurality of exposed ion conductive inorganic particles is 0.05 to 0.5. A first step of watering an ion conductive inorganic particle on at least one surface with a mixture comprising a polymerizable water-insoluble floating compound and a solvent;
A second step of stirring the resultant;
A third step of removing the solvent from the resultant product; And
A method for producing a composite membrane according to any one of claims 1 to 23, comprising the fourth step of carrying out a polymerization reaction. 25. The method of claim 24, wherein the moisture content of the ion conductive inorganic material particles is controlled to 100 ppm or less in the first step. 25. The method of claim 24,
Wherein the second step is performed by air blowing. 25. The method of claim 24,
In the first step, a hydrophobic coating film is formed on at least one side of the ion conductive inorganic particle,
The first step
a) a first floating casting step in which a part of the mixture comprising the polymerizable water-insoluble floating compound and the solvent is floated;
a-2) a second floating casting step of providing an ion conductive inorganic particle having a hydrophobic coating film on at least one side thereof, and floating the ion conductive inorganic particle in water; And
a-3) a third floating casting step of adding to the resultant the remainder of the mixture comprising the polymerizable water-insoluble floating compound and the solvent. 25. The method of claim 24,
Wherein the polymerizable water-insoluble floating compound is a water-
i) at least one polyfunctional monomer selected from a polyfunctional acrylic monomer and a polyfunctional vinyl monomer or
ii) a process for producing a composite membrane which is a mixture of a polyfunctional acrylic monomer and a polyfunctional monomer selected from polyfunctional monomers and polythiol having 3 or 4 thiol groups. 25. The method of claim 24,
In the first step, the ion conductive inorganic particle has a hydrophobic coating film formed on at least one surface thereof,
The ion conductive inorganic particle having the hydrophobic coating film disposed on at least one surface thereof
b-1) reacting ion conductive inorganic particles and a compound represented by the following formula (1) to obtain a reaction product; And
b-2) washing and drying the reaction product.
[Chemical Formula 1]

In the above formula (1), R ₁ to R ₃ independently represent a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C2-C20 alkenyl group, Substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C6-C20 aryloxy groups, substituted or unsubstituted C2-C20 alkynyl groups, substituted or unsubstituted C6-C20 aryl groups, substituted or unsubstituted C7- Or a substituted or unsubstituted C2-C20 heteroaryl group, a substituted or unsubstituted C2-C20 heteroaryloxy group, a substituted or unsubstituted C3-C20 heteroarylalkyl group, a substituted or unsubstituted C2-C20 heterocyclic group Or a halogen atom,
R ₄ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group or a substituted or unsubstituted C6-C20 aryl group. 25. The method of claim 24,
And the third step of removing the solvent is carried out at 25 to 60 占 폚. 25. The method of claim 24,
Wherein the content of the polymerizable water-insoluble floating compound is 10 to 1000 parts by weight based on 100 parts by weight of the ion conductive inorganic particles having the hydrophobic coating film disposed on at least one surface thereof. A negative electrode structure comprising a negative electrode and a composite membrane according to any one of claims 1 to 23. 32. A lithium secondary battery comprising the cathode structure of claim 32. The lithium secondary battery of claim 33, wherein the lithium secondary battery is a lithium air battery.

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