KR102160705B1 - Polymer solid electrolyte composition and polymer membrane comprising the same - Google Patents

Abstract

The present invention relates to a polymer solid electrolyte having high ionic conductivity, and by using the polymer solid electrolyte, it is possible to provide a lithium secondary battery with improved performance and enhanced safety.

Description

Polymer solid electrolyte composition and polymer membrane comprising the same {Polymer solid electrolyte composition and polymer membrane comprising the same}

The present invention relates to a polymer solid electrolyte composition and a polymer membrane comprising the same.

Lithium secondary batteries are used in various industries such as automobile batteries in small electronic devices including smartphones and notebook tablet PCs. These are developing in the technology direction of miniaturization, weight reduction, high performance, and high capacity.

Lithium secondary batteries include a negative electrode, a positive electrode, and an electrolyte.　Lithium, carbon, etc. are used as the negative active material of the lithium secondary battery, transition metal oxide, metal chalcogen compound, conductive polymer, etc. are used as the positive electrode active material, and liquid electrolyte, solid electrolyte, and polymer electrolyte are used as electrolytes. have.

Among them, the polymer electrolyte has the advantage of being environmentally friendly because there is no problem such as leakage of liquid generated in the liquid electrolyte, and it is easy to change the structure of the device in any desired shape because it can be thinned and processed in a film form.

The polymer electrolyte is a material composed of a polymer, a lithium salt, a non-aqueous organic solvent (optional), and other additives, and has excellent ionic conductivity, but there is a problem that the performance is much lower than that of a non-aqueous liquid electrolyte.

Accordingly, in order to overcome this problem, it is necessary to develop an ionic conductivity polymer electrolyte having high ionic conductivity at room temperature.

Republic of Korea Patent Publication No. 10-2013-001176 (2013.01.30) Block copolymer including a hydrophilic block and a hydrophobic block, a polymer electrolyte membrane and a fuel cell including the same

In order to solve the above problem, the present inventors conducted various studies to develop a polymer solid electrolyte having a new composition. As a result, a block polymer was mixed with an ion-supplying compound and an oxidizing agent to form a solution, and then a polymer membrane was prepared. The present invention was completed by confirming that the performance and safety of the lithium secondary battery can be improved by having high ionic conductivity.

Accordingly, an object of the present invention is to provide a polymer solid electrolyte composition for preparing a polymer solid electrolyte.

In addition, the present invention is to provide a polymer membrane made of the polymer solid electrolyte composition.

In addition, the present invention is to provide a lithium secondary battery including a polymer membrane made of the polymer solid electrolyte composition.

In order to achieve the above object, the present invention is an ion supply compound; A block polymer including an amorphous first block and an amorphous second block; And it provides a polymer solid electrolyte composition comprising an oxidizing agent.

In addition, the present invention provides a polymer membrane made of the polymer solid electrolyte composition.

In addition, the present invention provides a lithium secondary battery including the polymer membrane.

The polymer solid electrolyte composition according to the present invention improves the stability of a lithium secondary battery by securing high ionic conductivity.

1 is a cross-sectional view showing a lithium secondary battery according to the present invention.

In the present invention, after preparing a polymer solid electrolyte composition with improved ionic conductivity including a block polymer, a technology for applying it to a lithium secondary battery is proposed.

Polymer solid electrolyte composition

The polymer solid electrolyte composition according to the present invention comprises an ion supply compound; A block polymer including an amorphous first block and an amorphous second block; And a polymer solid electrolyte composition containing an oxidizing agent.

The ion supplying compound used in the preparation of the polymer solid electrolyte composition of the present invention can improve lithium ion conductivity, and according to an embodiment of the present invention, the ion supplying compound may be a lithium salt.

The lithium salt is, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , LiSCN, Li(FSO ₂ ) ₂ N LiCF ₃ CO ₂ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiTFSI, LiFSI, LiOH, LiOHH ₂ O, LiBOB, LiN(SO ₂ C ₂ F ₅ ) ₂ , LiC ₄ F ₉ SO ₃ , LiC(CF ₃ SO ₂ ) ₃ , (CF ₃ SO ₂ ) ₂ NLi, LiOH.H ₂ O, LiB(C ₂ O ₄ ) ₂ , chloroborane lithium, lower aliphatic carboxylic acid lithium, tetraphenylborate lithium, lithium One kind of lithium salt selected from the group consisting of imides and combinations thereof may be used.

Preferably, the ion supplying compound is preferably contained in an amount of 10 to 30% by weight, preferably 15 to 25% by weight, in the total polymer solid electrolyte. If the content of the ion-supplying compound is less than the above range, it is not easy to secure the lithium ion conductivity. On the contrary, if the content of the ion supplying compound is less than the above range, there is no significant increase in the effect and it is uneconomical, so it is appropriately selected within the above range.

The polymer solid electrolyte composition of the present invention may include a block polymer. The block is a part of a molecule contained in a polymer and is composed of a plurality of constituent units, and a block is referred to as a block that is different in chemical structure or three-dimensional arrangement from another part that contacts the part.

Accordingly, in the present invention, ionic conductivity may be improved by structural characteristics between blocks included in the block polymer, and the block polymer may include an amorphous first block and an amorphous second block.

The amorphous first block may be a block represented by the following [Chemical Formula 1] in one example.

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, an alkylene group, an alkenylene group, an alkynylene group, -C(=O)-X ₁ -or -X ₁ -C(=O)-, wherein X ₁ is an oxygen atom, a sulfur atom, -S(=O) ₂ -, an alkylene group, an alkenylene group, or It is an alkynylene group, and Y is a monovalent substituent including a ring structure to which a chain having 8 or more chain forming atoms is connected.

The term "single bond" as used in the present application means that no separate atom exists at the site. For example, if X is a single bond in Formula 1, a structure in which Y is directly linked to a polymer chain may be implemented.

The term "alkyl group" as used herein, unless otherwise specified, is a straight chain, branched chain or cyclic having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms It may be an alkyl group of, which may be optionally substituted by one or more substituents (however, when the aforementioned side chain is an alkyl group, the alkyl group may be 8 or more, 9 or more, 10 or more, 11 or more, or It may contain 12 or more carbon atoms, and the number of carbon atoms in this alkyl group may be 30 or less, 25 or less, 20 or less, or 16 or less).

The term "alkenyl group" or "alkynyl group" as used herein, unless otherwise specified, is a straight chain having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms , It may be a branched or cyclic alkenyl group or an alkynyl group, which may be optionally substituted by one or more substituents (however, the alkenyl group or alkynyl group as the side chain chain described above is 8 or more, 9 or more. , 10 or more, 11 or more, or 12 or more carbon atoms may be included, and the number of carbon atoms of the alkenyl group or alkynyl group may be 30 or less, 25 or less, 20 or less, or 16 or less. ).

The term "alkylene group" as used herein, unless otherwise specified, is a straight chain, branched chain or ring having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms It may be an alkylene group of the type, which may be optionally substituted by one or more substituents.

The term "alkenylene group" or "alkynylene group" as used herein, unless otherwise specified, includes 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. It may be a straight chain, branched chain or cyclic alkylene group, which may be optionally substituted by one or more substituents.

In addition, X in Formula 1 may be -C(=O)O- or -OC(=O)- in other examples.

In Formula 1, Y is a substituent including the aforementioned chain, and may be, for example, a substituent including an aromatic structure having 6 to 18 carbon atoms or 6 to 12 carbon atoms. The chain may be, for example, a straight chain alkyl group including 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more carbon atoms. This alkyl group may contain 30 or less, 25 or less, 20 or less, or 16 or less carbon atoms. These chains may be connected directly to the aromatic structure or via the aforementioned linker.

The first block may be represented by Formula 2 below in another example.

[Formula 2]

In Formula 2, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, X is -C(=O)-O-, P is an arylene group having 6 to 12 carbon atoms, Q is an oxygen atom, and Z is a chain formation It is the chain having 8 or more atoms.

In Formula 2, P may be phenylene in another example, and Z may be a straight-chain alkyl group having 9 to 20 carbon atoms, 9 to 18 carbon atoms, or 9 to 16 carbon atoms in another example. In the case where P is phenylene, Q may be connected to the para position of the phenylene. In the above, the alkyl group, arylene group, phenylene group and chain may be optionally substituted with one or more substituents.

The amorphous second block may be a block represented by the following [Chemical Formula 3] in one example.

[Formula 3]

In Formula 3, X ₂ is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, an alkylene group, an alkenylene group, an alkynylene group, -C(=O)-X ₁ -or -X ₁ -C(=O)-, wherein X ₁ is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, an alkylene group, an alkenylene group, or an alkynylene group, and W is at least one It is an aryl group containing a halogen atom.

In Chemical Formula 3, X ₂ may be a single bond or an alkylene group in other examples.

In Formula 3, the aryl group of W may be an aryl group having 6 to 12 carbon atoms or a phenyl group, and such aryl group or phenyl group may be 1 or more, 2 or more, 3 or more, 4 or more, or 5 or more halogen atoms It may include. In the above, the number of halogen atoms may be, for example, 30 or less, 25 or less, 20 or less, 15 or less, or 10 or less. As the halogen atom, a fluorine atom may be exemplified.

The block of Formula 3 may be represented by Formula 4 below in another example.

[Formula 4]

In Formula 4, X ₂ is as defined in Formula 2, R ₁ to R ₅ are each independently hydrogen, an alkyl group, a haloalkyl group, or a halogen atom, and the number of halogen atoms included in R ₁ to R ₅ is 1 That's it.

In Formula 4, R ₁ to R ₅ may each independently be a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, or a halogen, wherein the halogen may be chlorine or fluorine.

2 or more, 3 or more, 4 or more, 5 or more, or 6 or more of R ₁ to R ₅ in Formula 4 may include halogen. The upper limit of the number of halogens is not particularly limited, and may be, for example, 12 or less, 8 or less, or 7 or less.

The block copolymer may be a block copolymer including any one or both of the two types of amorphous blocks together with the other third block, or including only the two types of blocks. A third block that may be included in addition to the above two amorphous blocks may be crystalline or amorphous. Specific examples of the third block include, but are not limited to, poly (meth)acrylates, polyalkylene oxides, polyolefins, and polythiophenes. The sum of the first block and the second block may be 70 to 100% by weight of the total weight of the block polymer, and the third block may be less than 30% by weight of the total weight of the block polymer.

In this case, the d-spacing value of at least one of the first block and the second block may be 0.1 to 10 nm. The d-spacing may be measured by GIWAXS (Grazing-Incidence Wide-Angle X-ray Scattering), and if the d-spacing is less than or exceeds the above range, the ionic conductivity may be lowered.

The block polymer may further include a third block, and the third block may be crystalline or amorphous. In addition, the content of the third block may be less than 30% by weight based on the total weight of the block polymer. If the third block exceeds 30% by weight, the ionic conductivity may decrease.

The block is a part of a molecule contained in a polymer and is composed of a plurality of constituent units, and a block is referred to as a block that is different in chemical structure or three-dimensional arrangement from another part that contacts the part.

The oxidizing agent used in the preparation of the polymer solid electrolyte composition of the present invention may form an ionic conductivity polymer together with the ion supplying compound.

The oxidizing agent is an organic compound having a strong electron withdrawing group and is not particularly limited as long as it is a compound capable of receiving electrons from a block polymer or an ion-supplying compound, but a persulfate group-containing compound, a cyan group-containing compound, a halogen group It may be selected from the group consisting of containing compounds. Specifically, the oxidizing agent is iron (III) p-toluenesulfonate, ammonium sulfate, ammonium persulfate, ammonium oxalate, ammonium perchlorate, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, It may be one or more selected from the group consisting of tetracyanoethylene and chloranyl. In particular, iron (III) p-toluenesulfonate, 2,3-dichloro-5,6 in terms of improving ionic conductivity and improving battery performance. Dicyano-1,4-benzoquinone, tetracyanoethylene, chloranyl and mixtures thereof may be preferred.

The solvent used in the preparation of the polymer solid electrolyte composition of the present invention may be a solvent capable of dissolving the ion-supplying compound. For example, the organic 　 solvent is methanol, ethanol, 2-propanol, butanol, and 2-ethoxyethanol , Isopropyl alcohol, ethyl acetate, butyl acetate, acetone, dichloroethane, acetonitrile, tetrahydrofuran, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosamide, 1,3-dimethyl-2-imidazolidinone, triethyl phosphate, and gamma-butyrolactone One or more selected from the group consisting of is possible.

The content of the solvent is limited in consideration of the viscosity of the final polymer solid electrolyte composition. That is, the higher the content of the solvent, the higher the viscosity of the final obtained composition, making the manufacturing process of the polymer solid electrolyte membrane difficult. Conversely, the smaller the amount of the solvent, the lower the viscosity, and thus the workability may decrease.

In addition, the solution viscosity at 30°C of the polymer solid electrolyte composition of the present invention is not particularly limited, but is preferably 200 to 1,000 cP, preferably 300 to 800 cP or less, and more preferably 500 to 700 cP. I can. This viscosity control makes it possible to secure a viscosity that improves processability in manufacturing a polymer solid electrolyte composition as a membrane.

If the viscosity exceeds the above range, the thickness in the transverse direction (TD) due to the decrease in the flatness of the coating solution becomes non-uniform and the fluidity disappears, making it difficult to apply uniformly. It can prevent the occurrence of stains due to excessive flow of the coating liquid, and causes the problem that the thickness of the mechanical direction (MD) becomes uneven.

The polymer solid electrolyte composition as described above has excellent electronic conductivity, and specifically, may have an ionic conductivity of 10 ^-8 S/cm or more.

Polymer solid Electrolyte membrane

The polymer solid electrolyte composition forms a polymer solid electrolyte membrane by performing a known film manufacturing process.

As a method of the said 　 film 　 molding, any suitable film 　 molding method, such as a solution casting method (solution casting method), a melt 　 extrusion method, a calender method or a compression molding method, can be mentioned. Among these 　 film 　 molding methods, a solution casting method (solution casting method) or a melt 　 extrusion method is preferable.

For example, a solution casting method (solution casting method) may be used for film production.

The solution casting method is performed by coating a polymer solid electrolyte composition. At this time, the polymer solid electrolyte composition may be directly coated on either the positive electrode or the negative electrode, or coated on a separate substrate and then separated to perform a process of laminating with the positive electrode and the negative electrode.

In this case, the substrate may be a glass substrate or a plastic substrate. The plastic substrates include polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, cellulose triacetic acid, cellulose diacetic acid, poly(meth)acrylic acid alkyl ester, poly(meth)acrylic acid ester copolymer, polyvinyl chloride, polyvinyl alcohol , Polycarbonate, polystyrene, cellophane, polyvinylidene chloride copolymer, polyamide, polyimide, vinyl chloride/vinyl acetate copolymer, polytetrafluoroethylene, and polytrifluoroethylene. have. Further, a composite material composed of two or more of these can be used, and a polyethylene terephthalate film excellent in light transmittance is particularly preferred. The thickness of the support is preferably 5 to 150 µm, more preferably 10 to 50 µm.

The coating is, for example, spin coating, dip coating, solvent casting, slot die coating, spray coating. Roll coating, extrusion coating, curtain coating, die coating, wire bar coating, knife coating, or the like can be used.

At this time, it is necessary to adjust the parameters in each process to produce a uniform film.

For example, in the case of spin coating, a coating process may be performed at 500 to 4000 rpm, or divided into two steps, and a device having a thickness gap of 10 to 200 μm may be used for doctor blade coating. In addition, when spray coating is performed, it may be performed by spraying at a number of injections between 5 and 100 times through an injection pressure of 0.5 to 20 MPa. The design of these processes and the selection of parameters can be controlled by a person skilled in the art.

After the coating, an additional film drying step may be performed.

At this time, 　 drying is different depending on the type and content ratio of each component or organic 　 solvent, but it is preferable to perform 30 seconds to 15 minutes at 60 to 100 ℃.

The drying may be performed by one of hot air drying, electromagnetic wave drying, vacuum drying, spray drying, drum drying, and freeze drying, and preferably hot air drying.

After the coating and drying are performed, the thickness of the polymer solid electrolyte membrane is formed to the thickness of the film to be finally manufactured, and if necessary, the coating-drying or coating step is performed at least once.

As another example, a melt extrusion method may be used for film production.

The melt-extrusion method includes, for example, a T-die method and an inflation method. The molding temperature is preferably 150 to 350°C, more preferably 200 to 300°C.

In the case of forming a film by the T-die method, a T-die is mounted on the tip of a known single-axis extruder or a twin-screw extruder, and the extruded film is wound in a form of a film to obtain a roll-shaped film.

If necessary, the heating melting may sequentially undergo a first heating melting, a filtering filter passing, and a second heating melting process. The melting 　 extruding 　 heating and melting temperature may be 170 ℃ to 320 ℃, preferably 200 ℃ to 300 ℃. After being melt-extruded from the T-die, it can be cooled and solidified using at least one metal drum maintained at 70°C to 140°C. In the case of using a drum (casting roll) in this way, it may be extruded under the above-described temperature condition or lower than that.

A specific method for preparing the polymer solid electrolyte membrane may be appropriately selected by a person skilled in the art.

Lithium secondary battery

The polymer solid electrolyte composition presented above can be applied to a lithium secondary battery due to physical properties such as high lithium ion conductivity.

In particular, the polymer solid electrolyte composition of the present invention has a form in which a block polymer is dispersed in a cured ion-supplying compound, and due to the structural characteristics of the block polymer, not only the ionic conductivity but also the electrical conductivity may be improved.

In addition, it is possible to further increase the voltage stability of the lithium secondary battery by solving problems (heat generation, explosion, film deterioration, etc.) that occur when the lithium secondary battery is driven due to heat resistance, durability, chemical resistance, and flame retardancy.

The polymer solid electrolyte presented in the present invention is applied to a lithium secondary battery, but can be preferably used as a polymer solid electrolyte.

1 is a cross-sectional view showing a lithium secondary battery 10 according to the present invention. Referring to FIG. 1, the lithium secondary battery 10 includes a positive electrode 11, a negative electrode 15, and an electrolyte interposed therebetween, wherein a polymer solid electrolyte 13 is used as the electrolyte, which is presented above. One polymer solid electrolyte is used.

The polymer solid electrolyte 13 presented above satisfies all of the characteristics such as electrochemically stable potential difference, low electrical conductivity, and high temperature stability, and exhibits high lithium ion conductivity, so it is preferably used as an electrolyte for a battery to achieve performance and thermal stability of the battery. To improve

In addition, the electrolyte 13 may further include a material used for this purpose in order to further increase the lithium ion conductivity.

If necessary, the polymer solid electrolyte 13 further includes an inorganic solid electrolyte or an organic solid electrolyte. The inorganic solid electrolyte is a ceramic-based material, a crystalline or amorphous and crystalline materials can be _{used, Thio-LISICON (Li 3.} 25 Ge 0 .25 P 0. 75 S 4), Li 2 S-SiS 2, LiI -Li ₂ S-SiS ₂ , LiI-Li ₂ SP ₂ S ₅ , LiI-Li ₂ SP ₂ O ₅ , LiI-Li ₃ PO ₄ -P ₂ S ₅ , Li ₂ SP ₂ S ₅ , Li ₃ PS ₄ , Li ₇ P ₃ S ₁₁ , Li ₂ OB ₂ O ₃ , Li ₂ OB ₂ O ₃ -P ₂ O ₅ , Li ₂ OV ₂ O ₅ -SiO ₂ , Li ₂ OB ₂ O ₃ , Li ₃ PO ₄ , Li ₂ O-Li ₂ WO ₄ -B ₂ O ₃ , LiPON, LiBON, Li ₂ O-SiO ₂ , LiI, Li ₃ N, Li ₅ La ₃ Ta ₂ O12, Li ₇ La ₃ Zr ₂ O ₁₂ , Li ₆ BaLa ₂ Ta ₂ O ₁₂ , Li ₃ PO _(4-3/2w) Nw (w is w<1), Li _{3 .} The inorganic solid electrolyte such as a _{6 Si 0 .6 P 0. 4 O} 4 is possible.

Examples of organic solid electrolytes include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, poly agitation lysine, polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, and other polymer materials. A mixture of lithium salts can be used. At this time, these may be used alone or in combination of at least one or more.

The specific application method to the polymer solid electrolyte 13 is not particularly limited in the present invention, and a known method may be selected or applied by a person having ordinary skill in the art.

The lithium secondary battery 10 to which the polymer solid electrolyte 13 can be applied as an electrolyte is not limited to the positive electrode 11 or the negative electrode 15, and in particular, a lithium-air battery, a lithium oxide battery, a lithium-sulfur battery operating at a high temperature. , Lithium metal batteries, and all-solid batteries.

The positive electrode 11 of the lithium secondary battery 10 may include a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as formula Li _{1 + x} Mn _{2 - x} O ₄ (0≦ _x ≦0.33), LiMnO ₃ , LiMn ₂ O ₃ , and LiMnO ₂ ; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; Ni site-type lithium nickel oxide represented by the formula LiNi _{1 - x} M _x O ₂ (M = Co, Mn, Al, Cu, Fe, Mg, B or Ga; 0.01≦x≦0.3); Formula LiMn _{2 - x} M _x O ₂ (M = Co, Ni, Fe, Cr, Zn or Ta; 0.01≤x≤0.1) or Li ₂ Mn ₃ MO ₈ (M = Fe, Co, Ni, Cu or Zn A lithium manganese composite oxide represented by ); A lithium manganese composite oxide having a spinel structure represented by LiNi _x Mn _{2 - x} O ₄ ; LiMn ₂ O _{4 in} which part of Li in the formula is substituted with alkaline earth metal ions; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , Cu ₂ Mo ₆ S ₈ , Chalcogenides such as FeS, CoS and MiS, scandium, ruthenium, titanium, vanadium, molybdenum, chromium, manganese, iron, cobalt, nickel, copper, zinc, etc. Oxide, sulfide or halide of may be used, and more specifically, TiS ₂ , ZrS ₂ , RuO ₂ , Co ₃ O ₄ , Mo ₆ S ₈ , V ₂ O _5, etc. may be used, but are limited thereto. no.

Such a positive electrode active material may be formed on the positive electrode current collector. The positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes to the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel, Surface-treated with nickel, titanium, silver or the like may be used. In this case, the positive electrode current collector may be in various forms such as a film, sheet, foil, net, porous material, foam, non-woven fabric having fine irregularities formed on the surface so as to increase adhesion to the positive electrode active material.

In addition, as the negative electrode 15, a negative electrode mixture layer having a negative electrode active material is formed on the negative electrode current collector, or a negative electrode mixture layer (eg, lithium foil) is used alone.

At this time, the type of the negative electrode current collector or the negative electrode mixture layer is not particularly limited in the present invention, and a known material may be used.

In addition, the negative electrode current collector is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, carbon on the surface of copper or stainless steel , Nickel, titanium, silver, etc. surface-treated, aluminum-cadmium alloy, etc. may be used. In addition, the negative electrode current collector, like the positive electrode current collector, may be used in various forms such as a film, sheet, foil, net, porous body, foam, non-woven fabric having fine irregularities on the surface.

In addition, the negative active material is one selected from the group consisting of crystalline artificial graphite, crystalline natural graphite, amorphous hard carbon, low crystalline soft carbon, carbon black, acetylene black, Ketjen black, Super-P, graphene, and fibrous carbon. Above carbon-based material, Si-based material, LixFe ₂ O ₃ (0≤x≤1), Li _x WO ₂ (0≤x≤1), Sn _x Me _{1 - x} Me' _y O _z (Me: Mn, Fe , Pb, Ge; Me': Al, B, P, Si, elements of groups 1, 2, and 3 of the periodic table, halogen; 0<x≤1;1≤y≤3; 1≤z≤8), etc. Metal complex oxide; Lithium metal; Lithium alloy; Silicon-based alloys; Tin-based alloys; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , Metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Titanium oxide; It may include lithium titanium oxide, but is not limited thereto.

In addition, the negative electrode active material is SnxMe _{1 - x} Me' _y O _z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of groups 1, 2 and 3 of the periodic table, Metal complex oxides such as halogen, 0<x≦1;1≦y≦3;1≦z≦8); SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO2 ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ and An oxide such as Bi ₂ O ₅ may be used, and a carbon-based negative active material such as crystalline carbon, amorphous carbon, or carbon composite may be used alone or in combination of two or more.

In this case, the electrode mixture layer may further include a binder resin, a conductive material, a filler, and other additives.

The binder resin is used for bonding of an electrode active material and a conductive material and bonding to a current collector. Examples of such binder resins include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetra Fluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, fluorine rubber, and various copolymers thereof.

The conductive material is used to further improve the conductivity of the electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery, and examples thereof include graphite such as natural graphite or artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Polyphenylene derivatives and the like can be used.

The filler is selectively used as a component that suppresses the expansion of the electrode, and is not particularly limited as long as it is a fibrous material without causing chemical changes to the battery, and examples thereof include olefin-based polymers such as polyethylene and polypropylene; Fibrous materials such as glass fiber and carbon fiber are used.

The shape of the lithium secondary battery 10 as described above is not particularly limited, and may be, for example, a jelly-roll type, a stack type, a stack-folding type (including a stack-Z-folding type), or a lamination-stack type, Preferably, it may be a stack-folding type.

After manufacturing an electrode assembly in which the negative electrode 15, the polymer solid electrolyte 13, and the positive electrode 11 are sequentially stacked, the electrode assembly is put into a battery case, and then sealed with a cap plate and a gasket to be assembled to form a lithium secondary battery. To manufacture.

At this time, the lithium secondary battery 10 can be classified into various batteries, such as lithium-sulfur batteries, lithium-air batteries, lithium-oxide batteries, and lithium all-solid batteries, depending on the material of the anode/cathode used. , Coin type, pouch type, etc., and can be divided into bulk type and thin film type according to the size. The structure and manufacturing method of these batteries are well known in this field, and thus detailed descriptions are omitted.

The lithium secondary battery 10 according to the present invention may be used as a power source for a device requiring high capacity and high rate characteristics. Specific examples of the device include a power tool that is driven by an electric motor; Electric vehicles including electric vehicles (EV), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the like; Electric two-wheeled vehicles including electric bicycles (E-bikes) and electric scooters (Escooter); Electric golf cart; Power storage systems, etc., but are not limited thereto.

Hereinafter, a preferred embodiment is presented to aid the understanding of the present invention, but the following examples are only illustrative of the present invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention, It is natural that such modifications and modifications fall within the appended claims.

Example 1

A block polymer poly(4-dodecyloctylphenyl methacrylate)-b-poly(pentafluorostyrene) (Mn 1.6 million, Mw/ Mn 1.15, 1 block to 2 blocks 62:38 parts by weight) 2 g was dissolved in 10 ml of a tetrahydrofuran solvent to prepare a solution.

To the solution, 1 g of chloranil as an oxidizing agent and 1 g of LiTFSI as an ion-supplying compound were added and dissolved to prepare a polymer solid electrolyte composition.

Thereafter, the polymer solid electrolyte composition was coated on a stainless electrode using a bar coater, dried at room temperature for one day, and heated in an oven at 180° C. for an additional day to prepare a polymer electrolyte membrane having a thickness of 130 μm.

Example 2

A block polymer containing poly(4-dodecyloctylphenyl methacrylate) as the amorphous first block, poly(pentafluorostyrene) as the amorphous second block, and polyethylene oxide as the third crystalline block poly(4-dodecyloctylphenyl methacrylate)-b-poly A solution was prepared by dissolving 2 g of (pentafluorostyrene)-b-polyethylene oxide (220,000 Mn, 1.30 Mw/Mn, 1 block + 2 blocks vs. 3 blocks 76:24 parts by weight) in 10 ml of tetrahydrofuran solvent.

To the solution, 1 g of chloranil as an oxidizing agent and 1 g of LiTFSI as an ion-supplying compound were added and dissolved to prepare a polymer solid electrolyte composition.

Thereafter, the polymer solid electrolyte composition was coated on a stainless electrode using a bar coater, dried at room temperature for one day, and heated in an oven at 180° C. for an additional day to prepare a polymer electrolyte membrane having a thickness of 130 μm.

Comparative Example 1: Preparation of polymer solid electrolyte composition

In the same manner as in Example 1, a polymer solid electrolyte composition and a polymer membrane were prepared by using poly(methyl metaacrylate) instead of a block polymer.

Experimental Example 1: Measurement of lithium ion conductivity

Maker: Using the impedance meter of the VSP model of Bio-Logic SAS, the lithium ion conductivity of the polymer solid electrolyte membranes prepared in the above Examples and Comparative Examples was measured, and the results are shown in Table 1 below.

Experimental example 2: d-spacing measurement

The d-spacing value was measured with GIWAXS (Grazing-Incidence Wide-Angle X-ray Scattering), and the results are shown in Table 1.

Example 1 Example 2 Comparative Example 1 Ion conductivity 3 x 10 ^-6 S/cm 5 x 10 ^-5 S/cm Not measurable d-spacing 0.48 nm 0.42 nm Not measurable

As a result, as shown in Table 1, in the case of Examples 1 and 2, the lithium ion conductivity was excellent, and the d-spacing value was in the range of 0.1 to 10 nm, whereas in the case of Comparative Example 1, the measurement of the lithium ion conductivity was It was impossible, and a peak that could measure d-spacing did not appear.

In the above, preferred embodiments of the present specification have been illustrated and described, but the present specification is not limited to the specific embodiments described above, and is generally used in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications may be made by those skilled in the art, and these modifications should not be understood individually from the technical idea or prospect of the present invention.

10: lithium secondary battery
11: anode
13: high molecular solid electrolyte
15: cathode

Claims (4)

Ion supplying compounds;
A block polymer comprising an amorphous first block, an amorphous second block, and a crystalline or amorphous third block; And
Including an oxidizing agent,
The first block includes poly(4-dodecyloctylphenyl methacrylate) (poly(4-dodecyloctylphenyl methacrylate)),
The second block is represented by the following formula (3),
[Formula 3]

In Formula 3, X ₂ is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, an alkylene group, an alkenylene group, an alkynylene group, -C(=O)-X ₁ -or -X ₁ -C(=O)-, wherein X ₁ is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, an alkylene group, an alkenylene group, or an alkynylene group, and W is at least one halogen It is an aryl group containing an atom,
The third block is a polymer solid electrolyte composition comprising poly(meth)acrylate, polyalkylene oxide, polyolefin or polythiophene. The method of claim 1,
The weight of the third block is less than 30% by weight of the total polymer solid polymer electrolyte composition. A polymer membrane comprising the polymer solid electrolyte composition of claim 1 or 2. The method of claim 3,
25 ℃ ionic conductivity of 10 ^-8 S / cm or more polymer membrane.

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