KR102033746B1 - Case for Secondary Battery Comprising Inner Sealant Layer Including Nanaporous Material and Lithium Secondary Battery Comprising the Same - Google Patents

Abstract

The present invention consists of a laminate sheet comprising an outer coating layer, an inner sealant layer, and a barrier layer positioned between the outer coating layer and the inner sealant layer, wherein the inner sealant layer is porous having an average pore size of 1 Å to 100 nm. It relates to a secondary battery case, characterized in that the coating layer or a porous film containing a nano-material.

Description

Case for Secondary Battery Comprising Inner Sealant Layer Including Porous Nano Material and Lithium Secondary Battery Comprising the Same {Case for Secondary Battery Comprising Inner Sealant Layer Including Nanaporous Material and Lithium Secondary Battery Comprising the Same}

The present invention relates to a case for a secondary battery including an inner sealant layer including a porous nanomaterial, and a lithium secondary battery including the same.

As the development and demand for mobile devices increases, the demand for secondary batteries as energy sources is increasing rapidly. Among them, lithium secondary batteries with high energy density and operating potential, long cycle life, and low self discharge rate Batteries have been commercialized and widely used.

These lithium secondary batteries are classified into cylindrical batteries, rectangular batteries, and pouch-type batteries according to their appearance. Due to the recent trend toward miniaturization of mobile devices, demand for thinner rectangular batteries and pouch-type batteries is increasing. Increasingly, there is a high interest in pouch-type batteries, which are easy to be modified in shape, inexpensive to manufacture, and low in weight.

In general, a pouch type secondary battery includes a non-aqueous electrolyte containing lithium salt in a state in which an electrode assembly having a porous separator interposed between a positive electrode and a negative electrode on which an active material is coated on a current collector is mounted inside a pouch type battery case. It is made of impregnated structure.

In such lithium secondary batteries, carbonate esters contained in the non-aqueous electrolyte solution during cycles cause deterioration or electrolysis due to an increase in the temperature inside the battery during abnormal charges and discharges, overcharges, or short circuits. As a result, a gas such as CO or CO ₂ is generated inside the battery, and as the internal pressure increases, a swelling phenomenon in which the case swells, and the internal resistance increases.

Furthermore, at high temperatures, the reaction between the lithium transition metal oxide, which is the cathode active material, and the electrolyte is promoted to generate byproducts that increase the resistance of the cathode, thereby rapidly decreasing the shelf life at high temperatures.

Specifically, a small amount of moisture may be included in the battery during the manufacturing process of the battery. In particular, in the case of a pouch type case, the possibility of moisture penetrating through the sealing portion is very high. In this case, if the electrolyte contains LiPF ₆ lithium salt, LiPF ₆ should exist in the form of ions of Li ⁺ and PF ₆ ⁻ , but unintended side reactions result in unstable PF ₅ as a byproduct, To form HF. This HF destroys the SEI layer and causes dissolution of the anode or creates vacancy between the electrodes, which is more pronounced at high temperatures.

In connection with this problem, some prior arts disclose techniques for incorporating certain moisture adsorbents in a cell. For example, Japanese Patent Application Laid-Open No. 1997-92255 discloses a technique of using a nonwoven fabric composed of ceramic short fibers such as alumina, alumina-silica, potassium titanate, and the like as a separator. Korean Patent Application Laid-Open No. 2000-0031096 discloses a technique for adding molecular sieve or fumed silica fine powder to an electrode, and Japanese Patent Application Laid-Open No. 2005-235591 adds an additive to reduce the generation of gas in an electrolyte. Disclosed is a technique. In addition, US Patent No. 6,337,153 discloses a sealed non-aqueous electrolyte battery in which an inorganic acid fine powder which adsorbs substances such as hydrofluoric acid and water in an electrode or electrolyte is contained in an outer body using a laminate sheet of metal foil and a resin film. have.

However, the above-described techniques are techniques for including a predetermined inorganic material in the form of an additive, such as an electrode, a separator, an electrolyte, or the like, constituting the electrode assembly. The mobility may be greatly reduced, and thus the conductivity may be reduced, thereby degrading the cell performance and causing various side reactions in the cell.

Therefore, there is a high need for a technology of a secondary battery that can improve safety and lifespan characteristics of a battery by effectively removing gas and moisture generated during a cycle or at a high temperature.

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

After extensive research and various experiments, the inventors of the present application, as will be described later, a coating layer containing a porous nanomaterial having an average pore size of 1 100 to 100 nm as the inner sealant layer of the secondary battery case or In the case of the porous film, it was confirmed that the desired effect can be achieved without increasing the volume of the battery, and the present invention was completed.

Therefore, the secondary battery case according to the present invention,

A laminate sheet comprising an outer coating layer, an inner sealant layer, and a barrier layer positioned between the outer coating layer and the inner sealant layer,

The inner sealant layer is characterized in that the coating layer or porous film containing a porous nanomaterial having an average pore size of 1 ~ 100 nm.

In more detail, the porous nanomaterial may have an average pore size of about 1 nm to about 50 nm.

According to the present invention, the coating layer or the porous film containing the porous nanomaterial as the inner sealant layer in the non-aqueous electrolyte solution during the cycle of the battery is abnormal, such as repeated charging and discharging, overcharging, or short circuit of long-term use As the internal pressure rises by absorbing gas components such as CO and CO ₂ generated by decomposition due to the increase of temperature inside the battery at a high and high absorption rate, the swelling phenomenon of the case is increased and the internal resistance is increased. It can prevent and effectively collect both the small amount of moisture generated in the battery and the moisture that can penetrate from the outside, thereby preventing side reactions between the moisture and the electrolyte, thereby ensuring the safety of the battery. There exists an effect which can suppress deterioration of battery performance, such as a capacity | capacitance.

As described above, the inner sealant layer may be a coating layer or a porous film, and specifically, the inner sealant layer may include a coating layer in which a porous nanomaterial is coated on one surface of a barrier layer, and a porous nanomaterial of a substrate. It may be a porous film or a porous film made of a porous nanomaterial contained in the voids.

The coating layer may be formed by dispersing a porous nanomaterial in a solvent together with a binder to prepare a coating composition, and applying the same to one surface of the barrier layer, followed by drying. At this time, the content of the porous nanomaterial, the binder, and the solvent may be appropriately selected in consideration of the bonding strength, rigidity, the degree of the desired effect. As such, when forming the inner sealant layer as a coating layer, a separate film fabrication process is not required, which is preferable in terms of process efficiency, and porous nano materials are more firmly bonded by a binder. The potential for nanomaterials to fall off can be reduced, resulting in fewer cell safety problems.

The porous film in which the porous nanomaterial is included in the pores of the substrate may be prepared by preparing a separate substrate having pores and dispersing the porous nanomaterial therein. At this time, the content of the porous nano-material may be appropriately selected in consideration of the degree of the desired effect and the effect on the battery performance. The porous film thus prepared is then bonded together with the outer coating layer and the barrier layer to form a laminate sheet. The porous film prepared as described above does not need a separate coating process, and simply sprays the porous nanomaterial on the substrate and disperses it, thereby simplifying the process and using the separate substrate together, thereby providing excellent mechanical rigidity.

Here, the substrate is a porous substrate having a plurality of pores, and the diameter of the pores is generally 0.01 ~ 10 ㎛, thickness is generally 10 ~ 50 ㎛ because the inner sealant layer is formed. As such a base material, For example, Olefin type polymers, such as a chemical resistance and hydrophobic polypropylene; Sheets or non-woven fabrics made of glass fiber or polyethylene may be used, but the present invention is not limited thereto.

Finally, the porous film made of a porous nanomaterial can be prepared by applying a coating composition in which the porous nanomaterial is dispersed in a solvent to a base substrate such as glass by spin coating, drying, and then peeling it from the base substrate. have. In this case, the content of the porous nanomaterial and the solvent may be appropriately selected in consideration of the extent to which the porous nanomaterials can form a film. The porous film thus prepared is then bonded together with the outer coating layer and the barrier layer to form a laminate sheet. The porous film prepared as described above may be weaker than the above structures in terms of its bonding force, but is made of only porous nanomaterials, and thus has the best capturing ability such as gas and moisture, thereby more effectively achieving the intended effect of the present invention. have.

As such, when the case for transfer paper according to the present invention is used, the present invention can achieve the intended effect without including the porous nanomaterial in the electrolyte solution, the electrode structure, and the like. The presence of the material lowers the lithium ion mobility, thereby reducing the conductivity, thereby degrading battery performance and solving a problem that may cause various side reactions in the battery.

In addition, the case for a secondary battery according to the present invention includes a coating layer or a porous film including a porous nanomaterial as an inner sealant layer, and may be based on the same case thickness than when the porous nanomaterial is coated on the inner surface of the case separately. At the same time it can include more porous material, having excellent capture capacity, such as gas and moisture, or has an excellent effect in that the case thickness can be reduced.

On the other hand, the porous nano-material having an average pore size of 1 ~ 100 nm may be an inorganic material, an organic material or an organic-inorganic composite material.

More specifically, aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin (Sn), silicon (Si), indium (In), gallium (Ga), oxygen (O), And it may be an inorganic material or an organic material based on one or more materials selected from the group consisting of carbon (C), or aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin ( Sn), silicon (Si), indium (In), gallium (Ga), oxygen (O), and carbon (C) based on one or more materials selected from the group, some of which may be other metals or organics It may be a modified inorganic material, organic material or organic-inorganic composite material.

Such materials include, for example, porous silica, activated alumina, titanium oxide, magnesium oxide, calcium silicate, magnesium silicate, activated carbon based materials, carbon nanotubes, fullerenes, clay mineral based materials, montmorillonite based materials, and zeolite based materials. Mesoporous-based materials, metal-organic frameworks (MOFs), organoaluminum compounds, organotitanium compounds, organosilicon compounds, organozinc compounds, organomagnesium compounds, organoindium compounds, organotin compounds, and the like. For example, the porous nanomaterial may be used alone or two or more kinds of materials may be used together.

Among these porous nanomaterials, in particular, a zeolite-based material, a mesoporous-based material, or a metal-organic framework (MOF) may be more preferably used.

The zeolitic material is a material having micropores having a pore size of 2 nm or less, and more specifically, may be natural zeolite or modified zeolite. Here, the natural zeolite is a material represented by (Si, Al) O ₄ , and is an inorganic material based on silicon (Si) and aluminum (Al), wherein the modified zeolite is a pre-treatment, ion exchange, It means a zeolite surface-modified by heat treatment or the like. Examples of ion exchange include ion exchange with Li or Ca. The zeolitic materials may be used in various ways without limitation as long as they are capable of capturing a gas or the like as an effect according to the present invention, and specific examples of the modified zeolite are known in the art. Omit the listing.

The mesoporous material is a material having a larger pore size than the zeolitic material and has mesopores of 2 nm to 50 nm. Examples of such mesoporous materials include mesoporous silica, mesoporous alumina, mesoporous carbon, and the like, each of which may be modified with an inorganic substance of an organic substance or another metal. Thus, the mesoporous material used in the present invention may be, for example, modified or unmodified mesoporous silica, modified or unmodified mesoporous alumina, or modified or unmodified mesoporous carbon, but the present invention If the material can exert the effect, it is not limited thereto.

As described above, the zeolite and mesoporous materials as porous nanomaterials of the present invention are basically composed of inorganic materials, and thus have excellent heat resistance, and among them, modified zeolites and modified mesoporous materials modified with the organic materials. The mesoporous carbon modified with silica, modified mesoporous alumina, and inorganic material can secure more chemical resistance and superior rigidity, compared with the polypropylene film used as the inner sealant layer. Battery safety can also be ensured from acting chemical reactions and physical shocks.

In addition, the metal organic structure is a new type of organic-inorganic composite material bonded three-dimensionally compared with a zeolite-based material which is a crystalline material having micropores or a mesoporous-based material having mesopores. It is characterized by having crystallinity which is an advantage of the system material, and having a pore size having both a microporous region (2 nm or less) and a mesoporous region (2 to 50 nm). Therefore, such a metal organic structure has a wide range of molecular sizes that can be collected, and is excellent in capturing gas molecules of various sizes existing in a battery.

From these properties, various porous nanomaterials can be selected and used depending on the purpose.

On the other hand, as another configuration of the laminate sheet, the outer coating layer should have excellent resistance from the external environment, it is made of a weather resistant polymer having a predetermined tensile strength and weather resistance, the weather resistant polymer is polyethylene phthalate (PET), polyethylene It may be phthalate (PEN) or nylon.

The barrier layer may be a metal layer in one specific example so as to exert a function of improving the strength of the case in addition to the function of preventing inflow or leakage of foreign substances such as gas and moisture, and the metal layer is, for example, Aluminum (Al), Iron (Fe), Copper (Cu), Tin (Sn), Nickel (Ni), Cobalt (Co), Silver (Ag), Stainless steel, Carbon (C), Chromium (Cr) , Manganese (Mn), and titanium (Ti) may be one metal selected from the group consisting of or alloys thereof, but is not limited thereto.

The present invention also provides a secondary battery including the secondary battery case, an electrode assembly, and an electrolyte, and the secondary battery is not particularly limited, and in detail, an electrolyte solution containing lithium salt is impregnated in the electrode assembly. , So-called lithium secondary battery.

The electrode assembly is composed of a positive electrode and a negative electrode to enable charge and discharge, for example, a structure in which the positive electrode and the negative electrode is laminated with a separator therebetween, a folding type (jelly-roll) type, a stacked type, or a stack / It can be done in a folding manner. The positive electrode and the negative electrode of the electrode assembly may have a form in which electrode tabs thereof protrude directly to the outside of the battery, or the electrode tabs may be connected to separate leads and protrude out of the battery.

The positive electrode is prepared by applying a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, followed by drying and pressing. If necessary, a filler may be further added to the mixture.

The positive electrode current collector is generally made to a thickness of 3 to 500 ㎛. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like may be used. The current collector may form fine irregularities on its surface to increase the adhesion of the positive electrode active material, and may be in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

The positive electrode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; 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 , LiMnO _2, and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , Cu ₂ V ₂ O ₇ and the like; Ni-site type lithium nickel oxide represented by the formula LiNi _1-x M _x O ₂ , wherein M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3; Formula LiMn _2-x M _x O ₂ (wherein M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (wherein M = Fe, Co, Lithium manganese composite oxide represented by Ni, Cu or Zn); Spinel-structure lithium manganese composite oxides represented by LiNi _x Mn _2-x O ₄ ; LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with alkaline earth metal ions; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ Although these etc. are mentioned, it is not limited only to these.

The conductive material is typically added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Such a conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon blacks such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component that assists the bonding of the active material and the conductive material to the current collector, and is generally added in an amount of 1 to 30 wt% based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for inhibiting expansion of the positive electrode, and is not particularly limited as long as it is a fibrous material without causing chemical change in the battery. Examples of the filler include olefinic polymers such as polyethylene and polypropylene; Fibrous materials, such as glass fiber and carbon fiber, are used.

The negative electrode is manufactured by coating, drying, and pressing the negative electrode active material on a negative electrode current collector, and optionally, the conductive material, binder, filler, and the like as described above may be further included.

The negative electrode current collector is generally made of a thickness of 3 ~ 500㎛. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like, aluminum-cadmium alloy, and the like can be used. In addition, like the positive electrode current collector, fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.

The negative electrode active material may be, for example, carbon such as hardly graphitized carbon or graphite carbon; Li _x Fe 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' Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen, 0 <x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8); Lithium metal; Lithium alloys; 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 , And metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The separator is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 ㎛ ㎛, thickness is generally 5 ~ 300 ㎛. As such a separator, for example, olefin polymers such as chemical resistance and hydrophobic polypropylene; Sheets made of glass fibers or polyethylene, nonwoven fabrics, and the like are used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

The electrolyte may be a lithium salt-containing non-aqueous electrolyte, and the lithium salt-containing non-aqueous electrolyte is composed of a non-aqueous electrolyte and a lithium salt, and a non-aqueous organic solvent, an organic solid electrolyte, an inorganic solid electrolyte, etc. may be used as the non-aqueous electrolyte. It is not limited only to these.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, and gamma Butyl lactone, 1,2-dimethoxy ethane, tetrahydroxy franc, 2-methyl tetrahydrofuran, dimethyl sulfoxide, 1,3-dioxorone, formamide, dimethylformamide, dioxolon , Acetonitrile, nitromethane, methyl formate, methyl acetate, phosphate triester, trimethoxy methane, dioxorone derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbo Aprotic organic solvents such as nate derivatives, tetrahydrofuran derivatives, ethers, methyl pyroionate and ethyl propionate can be used.

Examples of the organic solid electrolyte include polyethylene derivatives, polyethylene oxide derivatives, polypropylene oxide derivatives, phosphate ester polymers, polyedgetion lysine, polyester sulfides, polyvinyl alcohols, polyvinylidene fluorides, Polymerizers containing ionic dissociating groups and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides, sulfates, and the like of Li, such as Li ₄ SiO ₄ —LiI-LiOH, Li ₃ PO ₄ —Li ₂ S-SiS ₂ , and the like, may be used.

The lithium salt is a good material to be dissolved in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide.

In addition, in the electrolyte solution, for the purpose of improving the charge and discharge characteristics, flame retardancy, etc., for example, pyridine, triethyl phosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexaphosphate triamide, nitro Benzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxy ethanol, aluminum trichloride and the like may be added. . In some cases, in order to impart nonflammability, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further included, and carbon dioxide gas may be further included to improve high temperature storage characteristics, and FEC (Fluoro-Ethylene) may be further included. Carbonate), PRS (Propene sultone) may be further included.

In one specific example, lithium salts such as LiPF ₆ , LiClO ₄ , LiBF ₄ , LiN (SO ₂ CF ₃ ) _2, and the like, may be prepared by cyclic carbonate of EC or PC, which is a highly dielectric solvent, and DEC, DMC, or EMC, which are low viscosity solvents. Lithium salt-containing non-aqueous electrolyte may be prepared by adding to a mixed solvent of linear carbonate.

The present invention further provides a battery module including the secondary battery, a battery pack including the battery module, and a device including the battery pack.

Specific examples of the device include a mobile phone, a portable computer, a smart phone, a tablet PC, a smart pad, a netbook, a LEV (Light Electronic Vehicle), and a power tool that is driven by a battery motor; Electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and the like; Electric motorcycles including electric bicycles (E-bikes) and electric scooters (E-scooters); Electric golf carts; And an electric power storage device, but are not limited thereto.

Since the structure and manufacturing method of such a battery module, a battery pack, and a device are known in the art, detailed description thereof will be omitted herein.

As described above, the secondary battery case according to the present invention has an inner sealant layer of a laminate sheet having a thickness of 1 kPa to 100, consisting of an outer coating layer, an inner sealant layer, and a barrier layer positioned between the outer coating layer and the inner sealant layer. By constructing a coating layer or a porous film containing a porous nanomaterial having an average pore size of nm, by a simple and easy method without the increase in the overall volume of the cell, gas and moisture that can occur during the cycle or during high temperature storage Effective removal has the effect of solving problems such as battery thickness increase, ignition, battery performance deterioration and deterioration of life characteristics due to swelling.

Furthermore, when the porous nanomaterial including the inorganic material is included, the heat resistance is excellent, and chemical resistance, rigidity, etc. can be improved through the modification of the porous nanomaterial, so that the secondary battery may be reacted due to internal reaction of the battery or physical impact applied from the outside. There is also an effect that can greatly improve safety.

1 is a schematic diagram partially showing a manufacturing method and a result of the laminate sheet for a secondary battery case according to an embodiment of the present invention;
2 is a schematic diagram partially showing a method and a result of manufacturing a laminate sheet for a secondary battery case according to another embodiment of the present invention;
3 is a schematic diagram partially showing a method of manufacturing a laminate sheet for a secondary battery case and a resultant according to another embodiment of the present invention;

Hereinafter, although described with reference to the drawings according to an embodiment of the present invention, this is for easier understanding of the present invention, the scope of the present invention is not limited thereto.

1 to 3 are schematic views for explaining a method of manufacturing a laminate sheet for a secondary battery case according to an embodiment of the present invention in detail, and the cross-sectional view of the resulting structure is also shown schematically. .

First, referring to FIG. 1, a laminate sheet forming a case for a secondary battery according to an embodiment of the present invention has a structure in which an outer coating layer 110 and a barrier layer 120 are bonded to each other. On one side, a binder and a porous nanomaterial are applied by coating composition 140, which is dispersed in a solvent, and then dried to form a coating layer 130 as an inner sealant layer.

As described above, the inner sealant layer of the laminate sheet may be coated with a porous nanomaterial 131 on one surface of the barrier layer 120 together with a binder 132 to have an average pore size of 1 μm to 100 nm. Becomes

Next, referring to FIGS. 2 and 3, as a method of manufacturing a laminate sheet for a secondary battery case according to another embodiment of the present invention, a method of manufacturing an inner sealant layer into one film including a porous nanomaterial may be used. It is schematically illustrated.

Referring to FIG. 2, first, a glass 201 is prepared, and a coating composition 240 in which a porous nanomaterial is dispersed in a solvent is coated on the glass 201 and then dried. As such, when the coating composition 240 in which the porous nanomaterial is dispersed in the solvent is dried, the porous nanomaterial 231 is made of a 2D or 3D porous film. Thereafter, the laminate sheet may be manufactured by peeling it from the glass 201 and laminating and bonding the outer coating layer 210, the barrier layer 220, and the porous film 230 in order.

Here, the coating composition in which the porous nanomaterial is dispersed in a solvent is a sol, and the composition is applied onto the glass by spin coating or the like. At this time, the porous nano material in the composition has a 2D or 3D structure between nano materials through networking (networking), it is possible to manufacture a film form by drying the composition coated on the glass.

In addition, referring to Figure 3, there is shown a method of manufacturing a laminate sheet with a porous film comprising a porous nanomaterial without a separate coating process.

First, the substrate 301 having a pore in which the porous nanomaterial can be dispersed is prepared, and the porous nanomaterial 331 is dispersed in the pores of the substrate 301 by spraying the porous nanomaterial 331 on the substrate 301. To produce a porous film 330 as an inner sealant layer. Thereafter, the laminate may be manufactured by laminating and bonding the outer coating layer 310, the barrier layer 320, and the porous film 330 in order.

The secondary battery case made of a laminate sheet thus manufactured includes a porous nanomaterial having an innermost inner sealant layer having an average pore size of 1 mm 3 to 100 nm, so that the battery is stored for a cycle or at a high temperature without increasing the overall volume of the battery. By removing the gas and water, etc., which may occur during the process by a simple and easy method, there is an effect of solving problems such as battery thickness increase, ignition, battery performance deterioration and deterioration of life characteristics due to swelling.

However, the present invention is not limited to the configuration to be used as the laminate sheet manufactured by the above-described method, and if the inner sealant layer is a case for a secondary battery having a structure containing a porous nanomaterial, regardless of the manufacturing method of the invention in the scope of the present invention Of course included.

Those skilled in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Claims (17)

It consists of a laminate sheet consisting of a non-porous outer coating layer, a porous inner sealant layer, and a non-porous barrier layer of metal positioned between the outer coating layer and the inner sealant layer,
The porous inner sealant layer has a pore diameter of 0.01 to 10 μm and a porous film including porous nanomaterials or pores of a porous substrate, which is a sheet or nonwoven fabric made of one of an olefinic polymer, glass fiber, or polyethylene, or networking. ) Is a porous film having a 2D or 3D structure using only porous nanomaterials,
The porous nano-material is a secondary battery case, characterized in that having an average pore size of 1 Å to 100 nm that can absorb gas and moisture. delete delete The secondary battery case of claim 1, wherein the porous nano material is an inorganic material, an organic material, or an organic-inorganic composite material. The method of claim 1, wherein the porous nano material is aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin (Sn), silicon (Si), indium (In), gallium (Ga) , An inorganic material or an organic material based on one or more materials selected from the group consisting of oxygen (O) and carbon (C). The method of claim 1, wherein the porous nano material is aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin (Sn), silicon (Si), indium (In), gallium (Ga) ), Based on one or more materials selected from the group consisting of oxygen (O), and carbon (C), a part of which is an inorganic material, an organic material or an organic-inorganic composite material which is modified with another metal or organic material. A secondary battery case characterized by the above. The case of claim 1, wherein the porous nano material is a zeolite-based material, a mesoporous-based material, or a metal-organic framework (MOF). 8. The secondary battery case of claim 7, wherein the zeolite-based material is natural zeolite or modified zeolite. 8. The secondary battery case of claim 7, wherein the mesoporous material is modified or unmodified mesoporous silica, modified or unmodified mesoporous alumina, or modified or unmodified mesoporous carbon. The case of claim 1, wherein the outer coating layer is made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or nylon. delete delete A secondary battery comprising a secondary battery case, an electrode assembly, and an electrolyte according to claim 1. A battery module comprising the secondary battery according to claim 13. A battery pack comprising the battery module according to claim 14. Device comprising a battery pack according to claim 15. 17. The device of claim 16, wherein the device is a mobile phone, a portable computer, a smartphone, a tablet PC, a smart pad, a netbook, a light electronic vehicle (LEV), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, and power storage. Device selected from the group consisting of devices.

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