KR20190079171A - Hybrid solid electrolyte and secondary battery using the same - Google Patents

Abstract

The present invention relates to a composite solid electrolyte and a secondary battery using the same. More particularly, the present invention relates to a composite solid electrolyte comprising an intermediate layer containing a ceramic material and a liquid electrolyte and porous polymer layers formed on one side and the other side of the intermediate layer, and to a secondary battery using the same. The electrochemical characteristics of an all-solid-state secondary battery can be enhanced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a composite solid electrolyte and a secondary battery using the composite solid electrolyte.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite solid electrolyte and a secondary battery using the same. More particularly, the present invention relates to a technique for improving the electrochemical characteristics of an all solid secondary battery using a porous polymer layer.

Lithium secondary batteries have large electrochemical capacities, high operating potentials, and excellent charge / discharge cycle characteristics, so demand for portable information terminals, portable electronic devices, small household power storage devices, motorcycles, electric vehicles and hybrid electric vehicles . With the spread of such applications, improvement of safety and high performance of lithium secondary batteries are required.

Conventional lithium secondary batteries use a liquid electrolyte and are easily ignited when exposed to water in the air, thus posing a safety problem. These safety issues are becoming more and more common as electric vehicles become more visible.

Recently, all solid-state secondary batteries using a solid electrolyte made of an inorganic material, which is a nonflammable material, have been actively studied for the purpose of improving safety. BACKGROUND ART Solid-state secondary batteries are attracting attention as a next-generation secondary battery in terms of safety, high energy density, high output, long life, simplification of manufacturing process, enlargement / compactification of batteries, and low cost.

However, conventional solid electrolytes have been produced using solid-state ceramics or solid-state polymer electrolytes, but have low electrochemical characteristics due to their large interfacial resistance, and composite solid electrolytes containing organic and inorganic materials are also lower in solid electrolyte than solid electrolytes There is a problem in that the interface resistance and the high-rate characteristics and life characteristics of the all-solid secondary battery are low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide a composite solid electrolyte capable of improving electrochemical characteristics of an all solid secondary battery using a porous polymer layer such as a nonwoven polymer film, have.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and another problem which is not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a composite solid electrolyte including an intermediate layer including a ceramic material and a liquid electrolyte, and a porous polymer layer formed on one side and the other side of the intermediate layer.

Also, the composite solid electrolyte according to an embodiment of the present invention may include an intermediate layer including a ceramic material, a polymer and a liquid electrolyte, and a porous polymer layer formed on one side and the other side of the intermediate layer.

In addition, the porous polymer layer according to an embodiment of the present invention may include a polymer film in the form of a nonwoven fabric.

In addition, the polymer film according to an embodiment of the present invention may be formed by electrospinning.

Also, the polymer film according to an embodiment of the present invention includes a ceramic material, and the ceramic material included in the polymer film is preferably 20 parts by weight or less based on 100 parts by weight of the total ceramic material contained in the composite solid electrolyte Do.

According to an embodiment of the present invention, when the intermediate layer includes a ceramic material and a liquid electrolyte, the ceramic material contained in the intermediate layer is preferably 40 to 60 parts by weight based on 100 parts by weight of the intermediate layer.

According to an embodiment of the present invention, when the intermediate layer includes a ceramic material, a polymer and a liquid electrolyte, the ceramic material contained in the intermediate layer is preferably 30 to 70 parts by weight based on 100 parts by weight of the intermediate layer.

The thickness of the composite solid electrolyte according to an embodiment of the present invention is preferably 30 to 150 mu m.

Further, the liquid electrolyte according to an embodiment of the present invention is characterized in that a lithium salt or a sodium salt is dissolved in a non-aqueous organic solvent, an ionic liquid solvent, or a mixture thereof.

In addition, the non-aqueous organic solvent according to an embodiment of the present invention preferably includes at least one non-aqueous organic solvent selected from carbonate, ester, ether, ketone, alcohol and aprotic solvents Do.

In addition, the ionic liquid solvent according to an embodiment of the present invention may be an imidazolium, pyridinium, pyrrolidinium, sulfonium, pyrazolium, It is preferable to include at least one ionic liquid solvent selected from ammonium, morpholinium, phosphonium, and piperidinium.

In addition, the lithium salt according to an embodiment of the present invention may be selected from the group consisting of LiClO ₄ , LiPF ₆ , CF ₃ SO ₂ NLiSO ₂ CF ₃ (LiTFSI), Li [N (SO ₂ F) ₂ ] C ₂ O ₄ ) ₂ ] (LiBOB), LiAsF _6, and lithium fluorosulfonyl-trifluoromethanesulfonylimide (LiFTFSI).

Also, the sodium salt according to an embodiment of the present invention is _{NaClO 4, NaPF 4, NaPF 6} , NaAsF 6, NaTFSI, Na [(C 2 F 5) 3 PF 3] (NaFAP), Na [B (C 2 _{O 4) 2] (NaBOB)} , Na [N (SO 2 F) 2] it is preferable to include the sodium salt at least one selected from (NaFSI) and _{NaBeti (NaN [SO 2 C 2} F 5] 2) .

The ceramic material according to an embodiment of the present invention may be at least one selected from the group consisting of lithium oxide, lithium sulfide, lithium phosphoric acid, amorphous ion conductive material, NASICON, sodium sulfide, and sodium oxide It is preferable to include a ceramic material.

In addition, the lithium oxide based ceramic material according to an embodiment of the present invention may be formed of a material selected from the group consisting of Al ₂ O ₃ , β-Al ₂ O ₃ , TiO ₂ , BaTiO ₃ , SiO ₂ , (La, Li) TiO ₃ (LLTO) La, Li) = La or Li), Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₆ La ₂ CaTa ₂ O ₁₂ , Li ₄ SiO ₄ Li ₃ BO _2.5 N _0.5 , Li ₉ SiAlO ₈ , Li ₆ La ₂ ANb ₂ At least one ceramic material selected from O ₁₂ (A = Ca or Sr), Li ₂ Nd ₃ TeSbO ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ (LLZO), Li ₅ La ₃ Ta ₂ O ₁₂ and Li ₉ SiAlO ₈ .

In addition, the lithium sulfide-based ceramic material according to an embodiment of the present invention includes Li ₁₀ GeP ₂ S ₁₂ , Li ₇ P ₂ S ₁₁ , Li _{3 . 25 Ge 0 .25 P 0. 75 S} 4 (LGPS), Li 2 S-Si 2 S 5, Li 2 S-Ga 2 S 3 -GeS 2, Li 2 S-Sb 2 S 3 -GeS 2, Li 2 SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -Li ₄ SiO _4, and Li _{3 .25} -Ge _{0 .25} -P _{0. 75} S ₄ (Thio-LISICON) desirable.

In addition, the lithium phosphorus-based ceramic material in accordance with one embodiment of the present invention _{LAGP (Li 1 + x Al x} Ge 2-x (PO 4) 3) (O <x <2), LTAP (Li 1 + x Ti _{2 - x Al x (PO 4} ) 3) (0 <x <2), Li 1 + x Ti 2 - x Al x Si y (PO 4) 3 -y (0 <x <2, 0 <y <3 ), At least one ceramic material selected from LiAl _x Zr _{2 -x} (PO ₄ ) ₃ (0 <x <2) and LiTi _x Zr _{2 -x} (PO ₄ ) ₃ .

In addition, the amorphous ion conductive material according to an embodiment of the present invention may be one selected from the group consisting of phosphorous-based glass, oxide-based glass, and oxide-sulfide based glass. Or more of the amorphous ionic conductivity material.

In addition, the sodium oxide based ceramic material according to an embodiment of the present invention is preferably Na ₃ Zr ₂ Si ₂ PO ₁₂ .

In addition, the polymer film according to an embodiment of the present invention may be a polyvinylidene fluoride (PVdF) system or a copolymer thereof, a poly (vinylidene fluoride-co-trifluoroethylene) system or a copolymer thereof, a polyethylene (PEO) or a copolymer thereof, a polyacrylonitrile (PAN) or a copolymer thereof, a poly (methyl methacrylate) (PMMA) system or a copolymer thereof, a polyvinyl chloride system or a copolymer thereof, (PU) or a copolymer thereof, a polypropylene (PP) system or a copolymer thereof, a polyimide (PI) system or a copolymer thereof, a polyethylene (PE) Or a copolymer thereof, a poly (propylene oxide) (PPO) system or a copolymer thereof, a poly (ethyleneimine) (PEI) system or a copolymer thereof, a poly (ethylene sulfide) (PES) system or a copolymer thereof, Acetate) (PVAc) system or a copolymer thereof, (Ethylene succinate) (PESc) or a copolymer thereof, a polyester-based or copolymer thereof, a polyamine-based or copolymer thereof, a polysulfide-based or copolymer thereof, a siloxane- (SBR) type or a copolymer thereof, a carboxymethyl cellulose (CMC) type or a copolymer thereof, and derivatives thereof.

In addition, the polymer included in the intermediate layer may include the above-mentioned polymer material that can be used for the polymer film.

In order to accomplish the above object, the secondary battery of the present invention may include the composite solid electrolyte described above.

The present invention relates to a method for manufacturing a composite solid electrolyte which is easy to mass-produce an intermediate layer comprising a ceramic material and a liquid electrolyte between two polymer films forming a composite solid electrolyte in a nonwoven form, And the energy density of the entire solid secondary battery can be increased.

In addition, the interface resistance of the solid secondary battery can be reduced, the life of the secondary battery can be extended, and the electrochemical characteristics of the solid battery can be improved.

Further, a large amount of liquid in the intermediate layer is absorbed into the polymer film formed in the nonwoven fabric form, so that the interface resistance with the electrode can be reduced, and the leakage of the liquid electrolyte contained in the intermediate layer can be suppressed.

In addition, the polymer film can be formed in the form of a nonwoven fabric to maintain a solid form, thereby improving the thermal and electrochemical stability of the secondary battery.

1 is a schematic diagram of a composite solid electrolyte according to an embodiment of the present invention.
2A is a cross-sectional SEM image of a composite solid electrolyte including a ceramic material and a liquid electrolyte as an intermediate layer according to an embodiment of the present invention.
2B is a cross-sectional SEM image of a composite solid electrolyte including a ceramic material, a polymer, and a liquid electrolyte as an intermediate layer according to an embodiment of the present invention.
3 is a charge / discharge graph of a battery composed of a composite solid electrolyte, a lithium negative electrode and a LiFePO ₄ anode according to an embodiment of the present invention.
FIG. 4 is a graph of lifetime characteristics according to current density of a composite solid electrolyte according to an embodiment of the present invention, a lithium negative electrode, and a battery composed of an LiFePO ₄ anode.
5 is a charge / discharge graph of a composite solid electrolyte according to an embodiment of the present invention, a lithium negative electrode and a battery composed of a LiNi _0.5 Mn _1.5 O ₄ positive electrode.
6 is a view showing a polymer film formed by electrospinning according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

1 is a view of a composite solid electrolyte according to one embodiment of the present invention.

Referring to FIG. 1, the composite solid electrolyte according to an embodiment of the present invention may include an intermediate layer including a ceramic material and a liquid electrolyte, and a porous polymer layer formed on one side and the other side of the intermediate layer.

The complex solid electrolyte according to an embodiment of the present invention may include an intermediate layer including a ceramic material, a polymer and a liquid electrolyte, and a porous polymer layer formed on one side and the other side of the intermediate layer. Can be formed.

Here, one side and the other side of the intermediate layer may be used to mean one side or the other side of the intermediate layer, or an upper side and a lower side of the intermediate layer, or a direction opposite thereto, and if it is formed on the upper surface of the intermediate layer An upper layer, and a lower layer when formed on the lower surface of the intermediate layer.

In addition, the intermediate layer and the polymer film may be formed in direct contact with each other, but the present invention is not limited thereto, and another layer may be formed therebetween.

Also, the porous polymer layer includes a porous polymer. The porous polymer is a non-uniform material in which small pores are dispersed in a polymer matrix, and is generally characterized by a low density.

The porous polymer layer according to an exemplary embodiment of the present invention may include a nonwoven polymer film, but is not limited thereto. The porous polymer layer may include a polymer material having many pores such as a mesh-type polymer film.

In addition, the ceramic material may exist in the form of particles, but it is not limited thereto and may exist in various forms, and may be dispersedly disposed in the intermediate layer.

The composite solid electrolyte according to an embodiment of the present invention can be manufactured by forming two layers of polymer films in the form of nonwoven fabric and forming an intermediate layer therebetween and is easy to mass-produce, The cost can be reduced, and the energy density of the entire solid secondary battery can be increased.

Preferably, the polymer film may be formed by electrospinning.

The polymer film may include a ceramic material, and the ceramic material included in the polymer film may be included in an amount of 20 parts by weight or less based on 100 parts by weight of the total ceramic material contained in the composite solid electrolyte.

This means that a part of the ceramic material contained in the intermediate layer can be impregnated with the polymer film, whereby the interface resistance between the ceramic particles made of a ceramic material, the interface resistance between the electrode and the electrolyte, Etc. can be reduced to improve the high-rate characteristics and the life characteristics, and the electrochemical characteristics of the solid-state cell can be improved.

At this time, the ceramic material is preferably a conductive ceramic material.

That is, a large amount of the liquid electrolyte in the middle layer is absorbed by the porous polymer layer such as a nonwoven polymer film or the like to reduce the interfacial resistance with the electrode, and the occurrence of leakage of the liquid electrolyte contained in the intermediate layer can be suppressed.

When the intermediate layer is formed of a ceramic material and a liquid electrolyte without a polymer, the ceramic material contained in the intermediate layer is 1 to 80 parts by weight, 1 to 70 parts by weight or 1 to 60 parts by weight based on 100 parts by weight of the intermediate layer More preferably 40 to 60 parts by weight.

The liquid electrolyte contained in the intermediate layer is preferably 1 to 80 parts by weight, 1 to 70 parts by weight or 1 to 60 parts by weight, more preferably 40 to 60 parts by weight, based on 100 parts by weight of the intermediate layer.

When the intermediate layer is formed of a ceramic material, a polymer and a liquid electrolyte, the amount of the ceramic material contained in the intermediate layer is preferably 1 to 80 parts by weight or 1 to 70 parts by weight, More preferably 70 parts by weight.

In this case, the amount of the liquid electrolyte contained in the intermediate layer is preferably 1 to 80 parts by weight or 1 to 70 parts by weight, more preferably 30 to 70 parts by weight based on 100 parts by weight of the intermediate layer.

The thickness of the composite solid electrolyte may be 30 to 200 탆, preferably 30 to 150 탆, and more preferably 40 to 90 탆.

In the complex solid electrolyte, the transfer mechanism of ions such as lithium or sodium can be described as follows.

Specifically, in the porous polymer layer, ions can be transferred by a transport mechanism or a transport mechanism and a segment motion of a polymer chain. In the intermediate layer, ion hopping through a ceramic material, a transport mechanism of a liquid electrolyte, Ions can be delivered by mechanisms.

The liquid electrolyte may be obtained by dissolving a lithium salt or a sodium salt in a non-aqueous organic solvent, an ionic liquid solvent, or a mixture thereof, but is not limited thereto and may be any type of liquid electrolyte conventionally used in the art .

Specifically, the liquid electrolyte may include at least one non-aqueous organic solvent selected from carbonate, ester, ether, ketone, alcohol, and aprotic solvents.

The liquid electrolyte may further include at least one selected from the group consisting of an imidazolium, a pyridinium, a pyrrolidinium, a sulfonium, a pyrazolium, an ammonium, a molybdenum And at least one ionic liquid solvent selected from the group consisting of Morpholinium, Phosphonium and Piperidinium.

In addition, the liquid electrolyte may be selected from the group consisting of LiClO ₄ , LiPF ₆ , CF ₃ SO ₂ NLiSO ₂ CF ₃ (LiTFSI), Li [N (SO ₂ F) ₂ ] (LiFSI), Li [B (C ₂ O ₄ ) ₂ ] LiBOB), LiAsF _6, and lithium difluoro a sulfonyl-tree can include one or more lithium salts is selected from the species such as a methanesulfonyl fluoro imide (LiFTFSI).

The liquid electrolyte may further include at least one of NaClO ₄ , NaPF ₄ , NaPF ₆ , NaAsF ₆ , NaTFSI, Na [(C ₂ F ₅ ) ₃ PF ₃ ] (NaFAP), Na [B (C ₂ O ₄ ) ₂ ] _{, Na [N (SO 2 F} ) 2] (NaFSI) and _{NaBeti (NaN [SO 2 C 2} F 5] 2) can comprise a sodium salt of at least one member selected from the like.

The intermediate layer may include at least one ceramic material selected from the group consisting of lithium oxide, lithium sulfide, lithium phosphoric acid, amorphous ion conductive material, NASICON, sodium sulfide, and sodium oxide.

Specifically, the intermediate layer is _{Al 2 O 3, β-Al} 2 O 3, TiO 2, BaTiO 3, SiO 2, (La, Li) TiO 3 (LLTO) ((La, Li) = La or Li), Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₆ La ₂ CaTa ₂ O ₁₂ , Li ₄ SiO ₄ Li ₃ BO _2.5 N _0.5 , Li ₉ SiAlO ₈ , Li ₆ La ₂ ANb ₂ O ₁₂ (A = Ca or Sr) ₂ Nd ₃ TeSbO ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ (LLZO), Li ₅ La ₃ Ta ₂ O ₁₂ and Li ₉ SiAlO _8, and the like. &Lt; / RTI &gt;

In addition, the intermediate layer is _{Li 10 GeP 2 S 12, Li} 7 P 2 S 11, Li 3 .25 Ge 0 .25 P 0 .75 S 4 (LGPS), Li 2 SSi 2 S 5, Li 2 S-Ga 2 S ₃ -GeS ₂ , Li ₂ S-Sb ₂ S ₃ -GeS ₂ , Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -Li ₄ SiO ₄ , and Li _{3 .25} -Ge _{0 .25} -P _0.75 S ₄ (Thio-LISICON), and the like, and may contain at least one lithium sulfide-based ceramic material containing sulfur in its crystal structure.

In addition, the intermediate layer is _{LAGP (Li 1 + x Al x} Ge 2 -x (PO 4) 3) (0 <x <2, more preferably 0 <x <1), LTAP (Li 1 + x Ti 2 - _{x Al x (PO 4) 3} ) (0 <x <2, more preferably 0 <x <1), Li 1 + x Ti 2 -x Al x Si y (PO 4) 3-y (0 <x <2, 0 <y <3 , more preferably 0 <x <1, 0 < y <1), LiAl x Zr 2 -x (PO 4) to ₃ (0 <x <2, more preferably 0 < based ceramic material selected from LiTi _x Zr _{2 -x} (PO ₄ ) ₃ (0 <x <2, more preferably 0 <x <1) have.

The intermediate layer may also include one or more amorphous ionic conductivity materials selected from phosphorous-based glass, oxide-based glass, and oxide-sulfide based glass. can do.

Further, the sodium oxide-based ceramic material may be Na ₃ Zr ₂ Si ₂ PO ₁₂ , &Lt; / RTI &gt; and the like.

The polymer film may be at least one selected from the group consisting of a polyvinylidene fluoride (PVdF) system or a copolymer thereof, a poly (vinylidene fluoride co-trifluoroethylene) system or copolymer thereof, a polyethylene glycol (PEO) (PMMA) or a copolymer thereof, a polyvinyl chloride-based or copolymer thereof, a polyvinylpyrrolidone (PVP) -based or copolymer thereof, an acrylonitrile (PAN) , Polyimide (PI) or copolymer thereof, polyethylene (PE) or copolymer thereof, polyurethane (PU) or copolymer thereof, polypropylene (PP) PPO) or a copolymer thereof, a poly (ethyleneimine) (PEI) system or a copolymer thereof, a poly (ethylene sulfide) (PES) system or a copolymer thereof, a poly (vinyl acetate) Poly (ethylene succinate) (PESc) based or Based copolymer or a copolymer thereof, a styrene-butadiene rubber (SBR) -based copolymer or a copolymer thereof, a copolymer thereof, a polyester-based or copolymer thereof, a polyamine-based copolymer or a copolymer thereof, a polysulfide-based copolymer or a siloxane- , Carboxymethylcellulose (CMC) or a copolymer thereof, and derivatives thereof, and the like.

The polymer contained in the intermediate layer may be at least one selected from the group consisting of a polyvinylidene fluoride (PVdF) system or a copolymer thereof, a poly (vinylidene fluoride co-trifluoroethylene) system or copolymer thereof, a polyethylene glycol (PEO) (PMMA) or a copolymer thereof, a polyvinyl chloride-based or copolymer thereof, a polyvinylpyrrolidone (PVP) -based or a polyvinylpyrrolidone (PVP) -based or polyvinylpyrrolidone (PI) or a copolymer thereof, a polyethylene (PE) or a copolymer thereof, a polyurethane (PU) or a copolymer thereof, a polypropylene (PP) (PES) or a copolymer thereof, poly (vinyl acetate) (PVAc) or a copolymer thereof, poly (ethyleneimine) (PEI) Copolymers, poly (ethylene succinate ) Or a copolymer thereof, a polyester-based or copolymer thereof, a polyamine-based or copolymer thereof, a polysulfide-based or copolymer thereof, a siloxane-based or copolymer thereof, a styrene butadiene rubber (SBR ) System or a copolymer thereof, a carboxymethyl cellulose (CMC) system or a copolymer thereof, and derivatives thereof, and the like.

Hereinafter, the additive for a lithium secondary battery according to the present invention will be described in more detail with reference to examples of the present invention. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

1. Example 1

A nonwoven fabric type polymer film to be used as an upper layer and a lower layer of the intermediate layer was prepared from polyacronitrile (PAN) nonwoven fabric.

Then, a 1 M LiPF ₆ lithium salt was dissolved in an EC / DMC solvent to prepare a liquid electrolyte.

Then, the liquid electrolyte and the LTAP ceramic material were mixed at a weight ratio of 40:60 between the upper and lower layers of the polymer film to form an intermediate layer.

2A is a cross-sectional SEM image of a composite solid electrolyte including a ceramic material and a liquid electrolyte as an intermediate layer according to an embodiment of the present invention.

The thickness of the composite solid electrolyte shown in FIG. 2A is about 90 μm.

2. Example 2

A nonwoven fabric type polymer film to be used as an upper layer and a lower layer of the intermediate layer was prepared from a polyacrylonitrile (PAN) nonwoven fabric.

Then, a 1 M LiPF ₆ lithium salt was dissolved in an EC / DMC solvent to prepare a liquid electrolyte.

Next, the liquid electrolyte, the LTAP ceramic material, and the PEO polymer were mixed at a weight ratio of 40:50:10 between the upper and lower layers of the polymer film to form an intermediate layer.

2B is a cross-sectional SEM image of a composite solid electrolyte including a ceramic material, a polymer, and a liquid electrolyte as an intermediate layer according to an embodiment of the present invention.

The thickness of the composite solid electrolyte shown in FIG. 2B is about 80 μm.

3. Example 3

A nonwoven fabric type polymer film to be used as an upper layer and a lower layer of the intermediate layer was prepared from polyvinylidene fluoride (PVdF) nonwoven fabric.

Next, a 1M LiTFSI lithium salt was dissolved in N-methyl-N-butylpyrrolidinium bis (trifluoromethylsulfonyl) imide (Py ₁₄ TFSI) ionic liquid to prepare a liquid electrolyte.

Then, the liquid electrolyte and the LAGP ceramic material were mixed in an amount of 40:60 wt% between the upper and lower layers of the polymer film to form an intermediate layer.

3 is a charge / discharge graph of a battery composed of a composite solid electrolyte, a lithium negative electrode and a LiFePO ₄ anode according to an embodiment of the present invention.

Specifically, FIG. 3 is a graph showing the charging / discharging characteristics of a battery in which the composite solid electrolyte according to Example 1 was manufactured using a lithium metal cathode and a LiFePO ₄ anode.

As shown in FIG. 3, the battery using the composite solid electrolyte according to an embodiment of the present invention exhibits excellent discharge capacity according to the current density (C-rate) and has a capacity of 100 mAh / g or more . &Lt; / RTI &gt;

FIG. 4 is a graph of lifetime characteristics according to current density of a composite solid electrolyte according to an embodiment of the present invention, a lithium negative electrode, and a battery composed of an LiFePO ₄ anode.

Specifically, FIG. 3 is a graph of lifetime characteristics according to current density of a battery in which a composite solid electrolyte according to Example 1 is manufactured using a lithium metal cathode and a LiFePO ₄ anode.

As shown in FIG. 4, in the battery using the composite solid electrolyte according to an embodiment of the present invention, the discharge capacity decreases according to the current density, but the capacity according to the cycle is maintained constant.

5 is a charge / discharge graph of a composite solid electrolyte according to an embodiment of the present invention, a lithium negative electrode and a battery composed of a LiNi _0.5 Mn _1.5 O ₄ positive electrode.

Specifically, the composite solid electrolyte according to Example 3 is a charge / discharge graph of a battery manufactured using a lithium metal anode and a LiNi _0.5 Mn _1.5 O ₄ anode.

As shown in FIG. 5, the battery using the composite solid electrolyte according to an embodiment of the present invention has excellent discharge capacity of 160 mAh / g.

6 is a view showing a polymer film formed by electrospinning according to an embodiment of the present invention.

Referring to FIG. 6, the polymer film according to one embodiment of the present invention may be formed by electrospinning. That is, since the polymer film is formed into a nonwoven fabric by electrospinning, a solid form can be maintained, and a large amount of liquid electrolyte in the middle layer can be absorbed by the nonwoven polymer film to reduce the interfacial resistance with the electrode, It is possible to suppress the occurrence of leakage of the liquid electrolyte contained in the liquid electrolyte.

The composite solid electrolyte according to one embodiment of the present invention can be manufactured in the following order. Specifically, a step of forming two polymer films in the form of a nonwoven fabric and an intermediate layer comprising a ceramic material and a liquid electrolyte or an intermediate layer containing a ceramic material, a polymer and a liquid electrolyte are formed between the polymer films to form a composite solid electrolyte . &Lt; / RTI &gt;

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible. Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

100, 200: Porous polymer layer
300: middle layer

Claims (22)

An intermediate layer comprising a ceramic material and a liquid electrolyte,
And a porous polymer layer formed on one side and the other side of the intermediate layer.
An intermediate layer comprising a ceramic material, a polymer and a liquid electrolyte,
And a porous polymer layer formed on one side and the other side of the intermediate layer.
3. The method according to claim 1 or 2,
Characterized in that the porous polymer layer comprises a polymer film in the form of a nonwoven fabric.
3. The method according to claim 1 or 2,
Wherein the polymer film is formed by electrospinning.
3. The method according to claim 1 or 2,
Wherein the polymer film comprises a ceramic material,
Wherein the ceramic material contained in the polymer film is 20 parts by weight or less based on 100 parts by weight of the total ceramic material contained in the composite solid electrolyte.
The method according to claim 1,
The ceramic material contained in the intermediate layer may include,
And 40 to 60 parts by weight per 100 parts by weight of the intermediate layer.
3. The method of claim 2,
The ceramic material contained in the intermediate layer may include,
And 30 to 70 parts by weight per 100 parts by weight of the intermediate layer.
3. The method according to claim 1 or 2,
Wherein the thickness of the composite solid electrolyte is 30 to 150 占 퐉.
3. The method according to claim 1 or 2,
Wherein the liquid electrolyte is prepared by dissolving a lithium salt or a sodium salt in a non-aqueous organic solvent, an ionic liquid solvent, or a mixture thereof.
10. The method of claim 9,
Wherein the non-aqueous organic solvent comprises at least one non-aqueous organic solvent selected from carbonate, ester, ether, ketone, alcohol and aprotic solvents.
10. The method of claim 9,
The ionic liquid solvent may be at least one selected from the group consisting of imidazolium, pyridinium, pyrrolidinium, sulfonium, pyrazolium, ammonium, At least one ionic liquid solvent selected from the group consisting of morpholinium, phosphonium, and piperidinium.
10. The method of claim 9,
The lithium salt may be LiClO ₄ , LiPF ₆ , CF ₃ SO ₂ NLiSO ₂ CF ₃ (LiTFSI), Li [N (SO ₂ F) ₂ ] (LiFSI), Li [B (C ₂ O ₄ ) ₂ ] , LiAsF _6, and lithium difluoro-sulfonyl-tree composite solid electrolyte characterized in that it comprises at least one lithium salt compound selected from fluoro methane sulfonyl imide (LiFTFSI) a.
10. The method of claim 9,
The sodium salt is _{NaClO 4, NaPF 4, NaPF 6} , NaAsF 6, NaTFSI, Na [(C 2 F 5) 3 PF 3] (NaFAP), Na [B (C 2 O 4) 2] (NaBOB), Na _{[N (SO 2 F) 2} ] (NaFSI) and _{NaBeti (NaN [SO 2 C 2} F 5] 2) a composite solid electrolyte characterized in that it comprises the sodium salt of at least one member selected from.
3. The method according to claim 1 or 2,
Wherein the ceramic material comprises at least one ceramic material selected from the group consisting of lithium oxide, lithium sulfide, lithium phosphoric acid, amorphous ion conductive material, NASICON, sodium sulfide, and sodium oxide. Solid electrolyte.
15. The method of claim 14,
The lithium oxide-based ceramic material is _{Al 2 O 3, β-Al} 2 O 3, TiO 2, BaTiO 3, SiO 2, (La, Li) TiO 3 (LLTO) ((La, Li) = La or Li), Li ₅ La ₃ Ta ₂ O ₁₂ , Li ₆ La ₂ CaTa ₂ O ₁₂ , Li ₄ SiO ₄ Li ₃ BO _2.5 N _0.5 , Li ₉ SiAlO ₈ , Li ₆ La ₂ ANb ₂ O ₁₂ (A = Ca or Sr) A composite solid electrolyte characterized by comprising at least one ceramic material selected from Li ₂ Nd ₃ TeSbO ₁₂ , Li ₇ La ₃ Zr ₂ O ₁₂ (LLZO), Li ₅ La ₃ Ta ₂ O ₁₂ and Li ₉ SiAlO ₈ .
15. The method of claim 14,
The lithium sulfide-based ceramic material is _{Li 10 GeP 2 S 12, Li} 7 P 2 S 11, Li 3.25 Ge 0.25 P 0.75 S 4 (LGPS), Li 2 S-Si 2 S 5, Li 2 S-Ga 2 S 3 -GeS ₂ , Li ₂ S-Sb ₂ S ₃ -GeS ₂ , Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -Li ₄ SiO ₄ and Li _{3 .25} -Ge _{0 .25} -P _{0 .75} S ₄ (Thio-LISICON). &Lt; / RTI &gt;
15. The method of claim 14,
Wherein the lithium-based ceramic material is _{LAGP (Li 1 + x Al x} Ge 2 -x (PO 4) 3) (O <x <2), LTAP (Li 1 + x Ti 2-x Al x (PO 4) 3 ) (0 <x <2) , Li 1 + x Ti 2 - x Al x Si y (PO 4) 3-y (0 <x <2, 0 <y <3), LiAl x Zr 2 -x (PO ₄ ) ₃ (0 <x <2) and LiTi _x Zr _{2 -x} (PO ₄ ) ₃ (0 <x <2).
15. The method of claim 14,
The amorphous ion conductive material includes at least one amorphous ion conductive material selected from phosphorousbased glass, oxide-based glass, and oxide-sulfide based glass. Lt; / RTI &gt;
15. The method of claim 14,
Wherein the sodium oxide-based ceramic material is Na ₃ Zr ₂ Si ₂ PO ₁₂ .
3. The method according to claim 1 or 2,
The polymer film may be at least one selected from the group consisting of a polyvinylidene fluoride (PVdF) system or a copolymer thereof, a poly (vinylidene fluoride-co-trifluoroethylene) system or copolymer thereof, a polyethylene glycol (PEO) Polyvinyl pyrrolidone (PVP) -based or polyvinylpyrrolidone (PVP) -based or copolymer thereof, polyacrylonitrile (PAN) -based or copolymer thereof, poly (methyl methacrylate) (PU) or a copolymer thereof, a polypropylene (PP) -based or copolymer thereof, a poly (propylene oxide) -based copolymer, a polyimide (PI) (PES) or a copolymer thereof, a poly (ethyleneimine) (PEI) system or a copolymer thereof, a poly (ethylene sulfide) (PES) system or a copolymer thereof, a poly (vinyl acetate) , Poly (ethylene succinate) (PESc) series or Based copolymer or a copolymer thereof, a styrene-butadiene rubber (SBR) -based copolymer or a copolymer thereof, a copolymer thereof, a polyester-based or copolymer thereof, a polyamine-based copolymer or a copolymer thereof, a polysulfide-based copolymer or a siloxane- , A carboxymethyl cellulose (CMC) system or a copolymer thereof, and derivatives thereof.
3. The method of claim 2,
The polymer may be at least one selected from the group consisting of a polyvinylidene fluoride (PVdF) system or a copolymer thereof, a poly (vinylidene fluoride-co-trifluoroethylene) system or copolymer thereof, a polyethylene glycol (PEO) (PMMA) or a copolymer thereof, a polyvinyl chloride-based or copolymer thereof, a polyvinylpyrrolidone (PVP) -based or copolymer thereof, an acrylonitrile (PAN) , Polyimide (PI) or copolymer thereof, polyethylene (PE) or copolymer thereof, polyurethane (PU) or copolymer thereof, polypropylene (PP) PPO) or a copolymer thereof, a poly (ethyleneimine) (PEI) system or a copolymer thereof, a poly (ethylene sulfide) (PES) system or a copolymer thereof, a poly (vinyl acetate) Poly (ethylene succinate) (PESc) based or poly Based or a copolymer thereof, a styrene-butadiene rubber (SBR) -based or copolymer thereof, a carboxy (meth) acrylate-based copolymer or a copolymer thereof, a polyamide-based or copolymer thereof, a polysulfide- Methyl cellulose (CMC) or a copolymer thereof, and derivatives thereof. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
A secondary battery comprising the composite solid electrolyte according to any one of claims 1 to 21.

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