KR20230171286A - Carbon dixode adsorbent, method for preparing the adsorbent, polyolefin-based composite comprising the polymer and case for secondary battery - Google Patents

Abstract

The present invention provides a carbon dioxide adsorbent that can improve stability by adsorbing gas generated during charging and discharging of a secondary battery and preventing seal failure of the secondary battery exterior material due to an increase in internal pressure of the secondary battery, a method of manufacturing the same, and a polyolefin containing the same. It relates to exterior materials for system composites and secondary batteries.

Description

Carbon dioxide adsorbent, manufacturing method thereof, polyolefin-based composite containing the same, and exterior material for secondary batteries {CARBON DIXODE ADSORBENT, METHOD FOR PREPARING THE ADSORBENT, POLYOLEFIN-BASED COMPOSITE COMPRISING THE POLYMER AND CASE FOR SECONDARY BATTERY}

The present invention relates to a carbon dioxide adsorbent, a method for manufacturing the same, a polyolefin-based composite containing the same, and an exterior material for a secondary battery.

Recently, the application area of lithium secondary batteries has rapidly expanded not only to power supply for electronic devices such as electricity, electronics, communication, and computers, but also to power storage and supply for large-area devices such as automobiles and power storage devices. Demand for stable lithium secondary batteries is increasing.

Lithium secondary batteries generally contain a positive electrode active material capable of inserting and desorbing lithium ions or a negative electrode active material capable of inserting and desorbing lithium ions, and a material that is optionally mixed with a binder and a conductive material in the positive and negative current collectors, respectively. It is manufactured by manufacturing a cathode and an anode by applying the electrode, stacking them on both sides of the separator to form an electrode assembly of a predetermined shape, and then inserting the electrode assembly and the non-aqueous electrolyte into a battery case.

Lithium secondary batteries can be divided into cylindrical secondary batteries, prismatic secondary batteries, pouch-type secondary batteries, etc. depending on their structure. Among these, the pouch-type secondary battery is manufactured by housing the electrode assembly in a pouch-type sheet and then sealing the sheet. Compared to other types of secondary batteries, the pouch-type secondary battery has a simple structure and a large capacity per unit volume, so it can be used in automobile batteries or energy storage devices. It is widely used.

The case of this pouch-type secondary battery is a pouch-type sheet to protect the electrodes and electrolyte from the outside and is composed of a metal film and a polymer material for sealing. At this time, the polymer material for sealing is a thermoplastic material made of olefin-based materials such as polypropylene and polyethylene, and heat-sealable materials are mainly used.

Meanwhile, lithium secondary batteries generate gas containing non-polar molecules such as carbon dioxide, carbon monoxide, methane, hydrocarbon, and hydrogen during the charging and discharging process. Among these, carbon dioxide accounts for the largest proportion, and the gas generated in this way is As a result, the pressure inside the sealed battery increases, and if the pressure continues to increase, the seal of the electric case may be destroyed.

Gas generated inside the pouch-type secondary battery cannot penetrate the metal membrane, and may be partially released through the polymer material. However, the polymer material does not have high permeability to the gas, making it difficult to suppress an increase in internal pressure.

As a solution to this problem, Patent Publication No. 10-2015-0015394 (Patent Document 1) discloses a battery case containing a carbon dioxide scavenger. However, according to Patent Document 1, the carbon dioxide scavenger is included in a separate coating layer or adsorption bag formed on the inner wall of the battery case, so a separate process for forming the coating layer or adsorption bag on the inner wall of the battery case is required. In addition, there is a problem that a separate space must be provided inside the battery case to form a coating layer and an adsorption bag.

Meanwhile, Patent Publication No. 10-2018-0006771 (Patent Document 2) discloses a carbon dioxide adsorbent and a method for manufacturing the same. However, according to Patent Document 2, the carbon dioxide adsorbent is a solid adsorbent and the presence of a porous support such as silica is essential to maintain its form. In addition, depending on the purpose of regenerative use according to the TSA process rather than secondary battery, the production of secondary amine is essential through stirring with epoxide to prevent deterioration of absorption capacity due to irreversible reaction of primary amine, 1 A reaction is essential for fixing the product of the reaction of stirring an aminosilane compound containing a secondary amine and an epoxide to a porous support by bonding through a condensation reaction. Therefore, the carbon dioxide adsorbent disclosed in Patent Document 2 is not suitable for application to exterior materials for secondary batteries.

Additionally, Patent Publication No. 10-2014-0147200 (Patent Document 3) discloses a carbon dioxide adsorption material using the crosslinking reaction of amine. However, according to Patent Document 3, the carbon dioxide adsorption material inevitably contains an excessive amount of amine due to the adsorption mechanism in which amine and carbon dioxide react. However, if an excessive amount of amine is included in the carbon dioxide adsorption material, the electrolyte inside the battery may react with the amine, causing denaturation of the electrolyte components, which may lead to a decrease in battery performance. Therefore, carbon dioxide adsorption materials containing an excessive amount of amines are not suitable for use in adsorbing carbon dioxide generated inside a battery.

KR 10-2015-0015394 A KR 10-2018-0006771 A KR 10-2014-0147200 A

The present invention was developed to solve the problems of the prior art, and improves stability by adsorbing the gas generated during charging and discharging of the secondary battery, preventing the sealing destruction of the secondary battery exterior material due to an increase in the internal pressure of the secondary battery. The purpose is to provide a carbon dioxide adsorbent that can be used.

Additionally, the present invention aims to provide a polyolefin-based composite containing the carbon dioxide adsorbent as an inner layer of an exterior material for a secondary battery.

In addition, the present invention aims to provide an exterior material for a secondary battery with improved stability by including the polyolefin-based composite, by adsorbing gas generated during charging and discharging of the secondary battery, and preventing seal failure due to an increase in the internal pressure of the secondary battery. Do it as

In order to solve the above problems, the present invention provides a carbon dioxide adsorbent, a method for producing a carbon dioxide adsorbent, a polyolefin-based composite, an exterior material for a secondary battery, and a lithium secondary battery.

(1) The present invention includes 50% by weight or more and 94% by weight or less of the origin of a multifunctional epoxy compound containing two or more epoxy groups; and 6% by weight or more and 50% by weight or less of an amine compound derived portion, wherein the multifunctional epoxy compound derived portion and the amine compound derived portion simultaneously contain an activating group represented by the following formula (1), and provide a carbon dioxide adsorbent in a solid state.

[Formula 1]

In Formula 1, R ¹ is the remainder of a multifunctional epoxy compound containing two or more epoxy groups, and R ² to R ⁴ are the remainder of an amine compound.

(2) In the present invention, in (1) above, the carbon dioxide adsorbent contains 80% by weight or more and 90% by weight or less of a portion derived from a polyfunctional epoxy compound containing two or more epoxy groups; and 10% by weight or more and 20% by weight or less of an amine compound derived portion.

(3) The present invention provides the carbon dioxide adsorbent according to (1) or (2) above, wherein the amine compound is at least one selected from the group consisting of primary amines, secondary amines, and tertiary amines.

(4) The present invention according to any one of (1) to (3) above, wherein R ¹ is the remainder of a polyfunctional epoxy compound containing 3 or more epoxy groups, and R ² to R ⁴ are each independently a primary amine. , providing a carbon dioxide adsorbent that is the remainder of one or more amine compounds selected from the group consisting of secondary amines and tertiary amines.

(5) The present invention according to any one of the above (1) to (4), wherein the molar ratio of the epoxy group of the origin of the polyfunctional epoxy compound and the epoxy group to the amine compound: amine compound is 3 to 100:1. Provides a carbon dioxide adsorbent.

(6) The present invention provides the carbon dioxide adsorbent according to any one of (1) to (5) above, wherein the activating group reacts with carbon dioxide to form a cyclic carbonate group.

(7) The present invention provides 50 to 94 parts by weight of a polyfunctional epoxy compound containing two or more epoxy groups and 6 to 50 parts by weight of an amine compound, based on a total of 100 parts by weight of the polyfunctional epoxy compound and the amine compound. Mixing the following (S10); and reacting the mixture mixed in step (S10) at a temperature of 50°C or more and 150°C or less (S20).

(8) The present invention provides a method for producing a carbon dioxide adsorbent in (7) above, wherein the step (S20) is performed for 0.5 hours or more and 24 hours or less.

(9) The present invention includes 60% by weight or more and 90% by weight or less of a continuous phase and 10% by weight or more and 40% by weight or less of a dispersed phase, the continuous phase includes a polyolefin resin, and the dispersed phase includes (1) to (6) above. ) It provides a polyolefin-based composite comprising a carbon dioxide adsorbent according to any one of the following.

(10) The present invention provides an exterior material for a secondary battery comprising the polyolefin-based composite according to (9) above in the inner skin.

(11) The present invention provides a lithium secondary battery including the exterior material for a secondary battery according to (10) above.

The carbon dioxide adsorbent of the present invention can improve stability by adsorbing gas generated during charging and discharging of a secondary battery, preventing seal failure of the secondary battery exterior material due to an increase in internal pressure of the secondary battery.

In addition, the carbon dioxide adsorbent of the present invention is a gas adsorbent and is contained in a dispersed form within the polyolefin-based composite used in the inner skin of the exterior material for secondary batteries, so a separate support such as a carrier or capsule is not required, and the carbon dioxide adsorbent is contained within the exterior material for secondary batteries. No separate space is required for coating or attaching.

In addition, since the carbon dioxide adsorbent of the present invention does not require a separate support such as a carrier or capsule, there is no need to select and provide a separate support when manufacturing the carbon dioxide adsorbent. Furthermore, the carbon dioxide adsorbent is not supported on a separate support or No process for fixing is necessary.

Figure 1 is a graph showing the FT-IR measurement results of the carbon dioxide adsorbent before and after evaluating the carbon dioxide adsorption capacity of the polyolefin-based composite prepared in Example 1 of the present invention according to Experimental Example 2.

Hereinafter, the present invention will be described in more detail to facilitate understanding of the present invention.

Terms or words used in the description and claims of the present invention should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately use the concepts of terms to explain his invention in the best way. Based on the principle of definability, it must be interpreted with meaning and concept consistent with the technical idea of the present invention.

carbon dioxide adsorbent

The present invention provides a carbon dioxide adsorbent that can improve stability by adsorbing gas generated during charging and discharging of a secondary battery and preventing seal failure of the secondary battery exterior material due to an increase in internal pressure of the secondary battery.

According to one embodiment of the present invention, the carbon dioxide adsorbent contains 50% by weight or more and 94% by weight or less of a portion derived from a multifunctional epoxy compound containing two or more epoxy groups; and 6% by weight or more and 50% by weight or less of an amine compound-derived portion, wherein the multifunctional epoxy compound-derived portion and the amine compound-derived portion simultaneously contain an activating group represented by the following formula (1), and may be in a solid state.

[Formula 1]

In Formula 1, R ¹ may be the remainder of a multifunctional epoxy compound containing two or more epoxy groups, and R ² to R ⁴ may be the remainder of an amine compound.

According to one embodiment of the present invention, the carbon dioxide adsorbent may be manufactured by the carbon dioxide adsorbent manufacturing method described later. Accordingly, the carbon dioxide adsorbent may include a multifunctional epoxy compound-derived portion formed from a multifunctional epoxy compound and an amine compound-derived portion formed from an amine compound. Here, the origin part may refer to the repeating unit itself, which includes both a binding part formed by each compound participating in the reaction and a functional group that does not participate in the reaction and maintains the functional group as is.

According to one embodiment of the present invention, the carbon dioxide adsorbent may contain at least 50% by weight, at least 60% by weight, at least 70% by weight, or at least 80% by weight of a portion derived from a multifunctional epoxy compound containing two or more epoxy groups. It may also include 94% by weight or less, 93% by weight or less, 92% by weight or less, 91% by weight or less, 90% by weight or less, or 85% by weight or less, and accordingly, 6% by weight or more of the amine compound derived portion. , may include at least 7% by weight, at least 8% by weight, at least 9% by weight, at least 10% by weight, or at least 15% by weight, and also at most 50% by weight, at most 40% by weight, at most 30% by weight, or It may contain 20% by weight or less. When the carbon dioxide adsorbent contains the polyfunctional epoxy compound-derived moiety and the amine compound-derived moiety in the content as described above, the epoxy group that can be converted to an activating group in the carbon dioxide adsorbent remains in a high content, thereby improving carbon dioxide adsorption and maintaining a solid state. there is.

According to one embodiment of the present invention, the carbon dioxide adsorbent may include an activating group represented by Formula 1, which is formed by reacting the epoxy group of the multifunctional epoxy compound with the amine compound. Accordingly, the multifunctional epoxy compound-derived portion and the amine compound-derived portion simultaneously include an activating group represented by Formula 1, and may be combined with an activating group represented by Formula 1.

According to one embodiment of the present invention, the multifunctional epoxy compound may include two or more epoxy groups. In the case of a monofunctional epoxy compound with one epoxy group, the epoxy group only acts to form a solid state by curing and does not maintain the activating group at a sufficient level, so carbon dioxide adsorption may be reduced. As a specific example, the multifunctional epoxy compound may contain three or more epoxy groups, and more specific examples include 1,4-butanediyl diglycidyl ether, 3-[bis(glycidyloxymedyl)methoxy]- 1,2-propanediol, diglycidyl 1,2-cyclohexanedicarboxylate, bisphenol A diglycidyl ether, tris(4-hydroxyphenyl)methane triglycidyl ether, trimethylolpropane triglycidyl At least one selected from the group consisting of ether, o-cresol novolak, poly(ethylene-co-glycidyl methacrylate), and poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate). You can.

According to one embodiment of the present invention, the amine compound may be an amine in the form of NH ₃ , but has the reactivity to form an activating group represented by Formula 1 according to the reaction between the epoxy group of the multifunctional epoxy compound and the amine compound. From the viewpoint of improvement, it may be one or more types selected from the group consisting of primary amines, secondary amines, and tertiary amines. As a specific example, the primary amine, secondary amine, and tertiary amine may each include an electron donating group.

According to one embodiment of the present invention, the amine compound is polyethyleneimine, tetraethylenepentamine, triethylenetetraamine, pentaethylenehexamine, diethylenetriamine, 2,4,6-tris(dimethylaminomethyl)phenol, etc. It may be one or more types selected from the group consisting of.

According to one embodiment of the present invention, the activating group represented by Formula 1 may vary depending on the type of the multifunctional epoxy compound and the amine compound. As a specific example, R ¹ is a multifunctional epoxy compound containing three or more epoxy groups. may be the remainder of, and R ² to R ⁴ may each independently be the remainder of one or more amine compounds selected from the group consisting of primary amines, secondary amines, and tertiary amines. As a more specific example, R ¹ is an epoxy group. It may be the remainder of a multifunctional epoxy compound containing three, and R ² to R ⁴ may each independently be the remainder of an amine compound of secondary amine or tertiary amine. Here, the remainder is the remainder of the polyfunctional epoxy compound excluding the epoxy group that participated in the reaction when forming the activating group represented by Formula 1 above by the reaction between the epoxy group of the polyfunctional epoxy compound and the amine compound, and the remainder of the amine compound. means.

According to one embodiment of the present invention, the carbon dioxide adsorbent has an epoxy group derived from the multifunctional epoxy compound and an epoxy group to the amine compound: amine compound molar ratio of 3 to 100:1, 3 to 90:1, or 3 to 80. :1, 3 to 70:1, 3 to 60:1, or 3 to 50:1, and within this range, the epoxy group in the carbon dioxide adsorbent remains in excess, and the activator continues to form due to reaction with the amine compound. It can be formed, and carbon dioxide adsorption can be further improved through reaction with carbon dioxide from the activated group formed in this way.

According to one embodiment of the present invention, the activating group may react with carbon dioxide to form a cyclic carbonate group. That is, the carbon dioxide adsorbent according to the present invention may adsorb carbon dioxide not by adsorbing carbon dioxide through a reaction between amine and carbon dioxide, but by reacting the activator with carbon dioxide to form a cyclic carbonate group. As a specific example, the reaction in which the activating group reacts with carbon dioxide to form a cyclic carbonate group may be represented by Scheme 1 below.

[Scheme 1]

As shown in Scheme 1, when the activating group reacts with carbon dioxide, a cyclic carbonate group is formed, and thus the amino group present in the state bound to the activating group is reduced to the form of the amine compound before reacting with the epoxy group, which is Through reaction with other epoxy groups remaining in the carbon dioxide adsorbent, an activating group represented by Formula 1 can be formed again. Therefore, the carbon dioxide adsorbent according to the present invention can maintain its carbon dioxide adsorption capacity depending on the content of epoxy groups remaining in the carbon dioxide adsorbent.

According to one embodiment of the present invention, it is important that the carbon dioxide adsorbent is in a solid state. If the carbon dioxide adsorbent is not in a solid state, is in a liquid state, or is not completely solidified and there are components that come out of the carbon dioxide adsorbent, a polyolefin-based composite cannot be formed according to the purpose of the present invention, and even if a polyolefin-based composite is manufactured, The carbon dioxide adsorbent does not exist in a dispersed phase within the polyolefin-based composite, but flows out of the polyolefin-based composite, making it impossible to secure carbon dioxide adsorption capacity. As a specific example, the carbon dioxide adsorbent is 200 ℃ or less, 190 ℃ or less, 180 ℃ or less, 170 ℃ or less, 160 ℃ or less, 150 ℃ or less, 140 ℃ or less, 130 ℃ or less, 120 ℃ or less, 110 ℃ or less, 100 ℃ or less , 90°C or less, 80°C or less, 70°C or less, 60°C or less, 50°C or less, 40°C or less, 30°C or less, or may be in a solid state at room temperature.

Carbon dioxide adsorbent manufacturing method

The present invention provides a manufacturing method for manufacturing the carbon dioxide adsorbent.

According to one embodiment of the present invention, the method for producing a carbon dioxide adsorbent includes 50 parts by weight or more and 94 parts by weight or less of a polyfunctional epoxy compound containing two or more epoxy groups, based on a total of 100 parts by weight of the polyfunctional epoxy compound and the amine compound. Mixing 6 parts by weight or more and 50 parts by weight or less of an amine compound (S10); And it may include a step (S20) of reacting the mixture mixed in step (S10) at a temperature of 50 ℃ or more and 150 ℃ or less.

According to one embodiment of the present invention, the (S10) step is a step of mixing reactants to form a carbon dioxide adsorbent, and for the purpose of the present invention, sufficient solidification is performed while increasing the content of epoxy groups remaining in the carbon dioxide adsorbent. In order to do this, the multifunctional epoxy compound is mixed in a content of at least the same amount or more than that of the amine compound. At this time, the types of the multifunctional epoxy compound and the amine compound and the molar ratio of the epoxy group and the amine compound in the multifunctional epoxy compound are the same as described above.

According to one embodiment of the present invention, the (S20) step may be a step for simultaneously curing and forming an activator by reaction between a multifunctional epoxy compound and an amine compound, and the reaction is carried out at 50° C. or higher, 60° C. It can be carried out at a temperature of 150 ℃ or higher, 70 ℃ or higher, 80 ℃ or higher, or 90 ℃ or higher, and also at a temperature of 150 ℃ or lower, 140 ℃ or lower, 130 ℃ or lower, 120 ℃ or lower, 110 ℃ or lower, or 100 ℃ or lower. It can be carried out in .

According to one embodiment of the present invention, the step (S20) may be performed for 0.5 hours or more, 1 hour or more, 1.5 hours or more, 2 hours or more, 3 hours or more, 4 hours or more, or 5 hours or more, and 24 hours or less, 22 hours or less, 20 hours or less, 18 hours or less, 16 hours or less, 14 hours or less, 12 hours or less, 10 hours or less, 9 hours or less, 8 hours or less, 7 hours, or less, or 6 hours or less It can be implemented.

Polyolefin-based composite

The present invention provides a polyolefin-based composite containing the carbon dioxide adsorbent as a gas adsorbent.

According to one embodiment of the present invention, the polyolefin-based composite includes 60% by weight or more and 90% by weight or less of a continuous phase and 10% by weight or more and 40% by weight or less of a dispersed phase, the continuous phase includes a polyolefin-based resin, and the dispersed phase may include the carbon dioxide adsorbent.

According to one embodiment of the present invention, the polyolefin-based composite includes a continuous phase and a dispersed phase, so that it has heat-sealability, has low hygroscopicity to the electrolyte solution to suppress the intrusion of the electrolyte solution, and does not swell or erode by the electrolyte solution. However, by adsorbing the gas generated during charging and discharging of the secondary battery, it is possible to improve the stability by preventing the sealing failure of the secondary battery exterior material due to an increase in the internal pressure of the secondary battery. As a specific example, the continuous phase includes a polyolefin-based resin that has heat-sealability, has low hygroscopicity to the electrolyte solution to prevent intrusion of the electrolyte solution, and does not swell or erode by the electrolyte solution, and the dispersed phase is used for charging and discharging of the secondary battery. It may include the carbon dioxide adsorbent, which can improve stability by adsorbing gas generated during operation and preventing the sealing failure of the secondary battery exterior material due to an increase in the internal pressure of the secondary battery.

According to one embodiment of the present invention, the polyolefin-based composite comprises at least 60% by weight, at least 65% by weight, or at least 70% by weight, and at most 90% by weight, at most 85% by weight, or at most 80% by weight of the continuous phase. may include 10 wt% or more, 15 wt% or more, or 20 wt% or more of the dispersed phase, and may also include 40 wt% or less, 35 wt% or less, or 30 wt% or less of the dispersed phase, and within this range, the continuous It is possible to simultaneously secure thermal adhesion by the phase and gas adsorption by the dispersed phase. When the content of the continuous phase is less than 60% by weight and the content of the dispersed phase is more than 40% by weight, the continuous phase is not sufficiently secured and the heat sealability of the polyolefin-based composite is lowered, and as a result, the polyolefin-based composite is used as an inner layer of the exterior material for a secondary battery. There is a problem that cannot be applied. In addition, when the content of the continuous phase is more than 90% by weight and the content of the dispersed phase is less than 10% by weight, gas adsorption by the dispersed phase cannot be secured, so there is no difference from the polyolefin resin that does not contain the dispersed phase.

According to one embodiment of the present invention, the polyolefin-based composite itself can be applied as the inner skin of an exterior material for a secondary battery. At this time, the polyolefin-based composite may be laminated on the inner wall of the exterior material for secondary batteries in the form of a film or sheet.

According to one embodiment of the present invention, the polyolefin-based composite can be manufactured by mixing the polyolefin-based resin to form a continuous phase and the carbon dioxide adsorbent to form a dispersed phase at a temperature higher than the melting point of the polyolefin-based resin. At this time, the polyolefin-based resin may be a polyolefin-based resin having a melting point of 200 ℃ or lower, 190 ℃ or lower, 180 ℃ or lower, 170 ℃ or lower, 160 ℃ or lower, or 150 ℃ or lower, and may also have a melting point of 100 ℃ or higher, 110 ℃ or higher. , it may be 120°C or higher, 130°C or higher, or 140°C or higher.

According to one embodiment of the present invention, the polyolefin-based composite may be manufactured in the form of a film or sheet by mixing the polyolefin-based resin and the carbon dioxide adsorbent and then extruding.

Exterior material for secondary batteries

The present invention provides an exterior material for secondary batteries.

According to one embodiment of the present invention, the exterior material for a secondary battery may include the polyolefin-based composite in the inner skin.

According to one embodiment of the present invention, the exterior material for a secondary battery may be a pouch-type battery case made of a laminate sheet, and the polyolefin-based composite may be included in the inner skin of the laminate sheet.

According to one embodiment of the present invention, the laminate sheet may have a laminated structure of an external resin layer, an air and moisture barrier metal layer, and a heat-sealable internal resin layer.

According to one embodiment of the present invention, the outer resin layer of the laminate sheet must have excellent resistance to the external environment, so tensile strength and weather resistance are required. Accordingly, the resin of the outer resin layer may include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and/or stretched nylon, which have excellent tensile strength and weather resistance.

According to one embodiment of the present invention, the metal layer is made of aluminum (Al) or an aluminum alloy so that it can exercise the function of improving the strength of the battery case in addition to preventing the inflow of foreign substances such as gas and moisture and/or leakage of electrolyte. This can be used. As a specific example, the aluminum alloy may have alloy numbers 8079, 1N30, 8021, 3003, 3004, 3005, 3104, 3105, etc., and may be used alone or in combination of two or more.

According to one embodiment of the present invention, the internal resin layer needs to use a resin that has heat-sealability, has low hygroscopicity to the electrolyte solution to suppress the intrusion of the electrolyte solution, and does not swell or erode by the electrolyte solution. At this time, the polyolefin-based composite has heat-sealability in a continuous phase, has low hygroscopicity to the electrolyte solution to suppress the intrusion of the electrolyte solution, and contains a polyolefin-based resin that does not swell or erode by the electrolyte solution, so the laminate sheet It may be included in the inner skin as the heat-sealable inner resin layer itself. Additionally, the polyolefin-based composite may be heat-sealed to the heat-sealable inner resin layer and may be additionally laminated. In this case, the heat-sealable inner resin layer may be a non-stretched polypropylene film (CPP).

Lithium secondary battery

The present invention provides a lithium secondary battery including the exterior material for the secondary battery.

According to one embodiment of the present invention, the lithium secondary battery may include an electrode assembly and an electrolyte accommodated in the exterior material for the secondary battery, and the electrode assembly includes a positive electrode; cathode; It may include a separator interposed between the anode and the cathode.

According to one embodiment of the present invention, the positive electrode may include a positive electrode current collector and a positive electrode active material layer located on the positive electrode current collector.

According to one embodiment of the present invention, the positive electrode current collector may include a highly conductive metal, and the positive electrode active material layer is easily adhered, but is not particularly limited as long as it is not reactive within the voltage range of the battery. The positive electrode current collector may be, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or an aluminum or stainless steel surface treated with carbon, nickel, titanium, silver, etc. Additionally, the positive electrode current collector may typically have a thickness of 3 ㎛ to 500 ㎛, and fine irregularities may be formed on the surface of the current collector to increase the adhesion of the positive electrode active material. For example, it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven materials.

According to one embodiment of the present invention, the positive electrode active material layer may optionally include a conductive material and a binder along with the positive electrode active material. At this time, the positive electrode active material may be included in an amount of 80% to 99% by weight, more specifically 85% to 98.5% by weight, based on the total weight of the positive electrode active material layer, and can exhibit excellent capacity characteristics within this range. there is.

According to one embodiment of the present invention, the positive electrode active material is LiCoO ₂ , LiCoPO ₄ , LiNiO ₂ , Li _x Ni _a Co _b M ¹ _c M ² _d O ₂ (M ¹ and M ² are each independently Al, Mn, One species selected from the group consisting of Cu, Fe, V, Cr, Mo, Ga, B, W, Mo, Nb, Mg, Hf, Ta, La, Ti, Sr, Ba, Ce, F, P, S and Y , 0.9≤x≤1.1, 0<a<1.0, 0<b<1.0, 0≤c<0.5, 0≤d<0.5, a+b+c+d=1.), LiMnO ₂ , LiMnO ₃ , LiMn ₂ O ₃ , LiMn ₂ O ₄ , LiMn _2-e M ³ _e O ₂ (M ³ is at least one selected from the group consisting of Co, Ni, Fe, Cr, Zn and Ta, 0.01≤e≤0.1 ), Li ₂ Mn ₃ M ⁴ O ₈ (M ⁴ is one or more selected from the group consisting of Ci, Ni, Fe, Cu and Zn), LiFePO ₄ , Li ₂ CuO ₂ , LiV ₃ O ₈ , It may be one type selected from the group consisting of V ₂ O ₅ , Cu ₂ V ₂ O ₇ and lithium metal.

According to one embodiment of the present invention, the binder of the positive electrode active material layer serves to improve adhesion between positive active material particles and adhesion between the positive active material and the current collector. Specific examples include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylalcohol, polyacrylonitrile, and polymethylmethane. Crylate (polymethymethaxrylate), carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene- Diene polymer (EPDM), sulfonated-EPDM, styrene butadiene rubber (SBR), fluoroelastomer, polyacrylic acid, and polymers whose hydrogens are substituted with Li, Na, or Ca, or various copolymers thereof Combinations, etc. may be mentioned, and one type of these may be used alone or a mixture of two or more types may be used. The binder may be included in an amount of 0.1% by weight to 15% by weight based on the total weight of the positive electrode active material layer.

According to one embodiment of the present invention, the conductive material of the positive active material layer is used to provide conductivity to the electrode, and can be used without particular limitation in the battery being constructed as long as it does not cause chemical change and has electronic conductivity. Specific examples include graphite such as natural graphite and artificial graphite; Carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, and carbon fiber; Metal powders or metal fibers such as copper, nickel, aluminum, and silver; Conductive tubes such as carbon nanotubes; Conductive whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Or conductive polymers such as polyphenylene derivatives, etc., of which one type alone or a mixture of two or more types may be used. The conductive material may be included in an amount of 0.1% to 15% by weight based on the total weight of the positive electrode active material layer.

According to one embodiment of the present invention, the positive electrode can be manufactured according to a conventional positive electrode manufacturing method. Specifically, the positive electrode is prepared by dissolving or dispersing the positive electrode active material and optionally a binder, a conductive material, and a dispersant in a solvent, and the composition for forming a positive active material layer is applied to the positive electrode current collector and then dried. and rolling, or by casting the composition for forming the positive electrode active material layer on a separate support and then peeling from this support and laminating the film obtained on the positive electrode current collector.

According to one embodiment of the present invention, the solvent may be a solvent commonly used in the art, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, and N-methylpyrrolidone. (NMP), dimethylformamide (DMF), acetone, or water, among which one type alone or a mixture of two or more types may be used. The amount of the solvent used is to dissolve or disperse the positive electrode active material, conductive material, binder, and dispersant in consideration of the application thickness and manufacturing yield of the slurry, and to have a viscosity capable of exhibiting excellent thickness uniformity when applied for subsequent positive electrode production. That's enough.

According to one embodiment of the present invention, the negative electrode may include a negative electrode current collector and a negative electrode active material layer located on the negative electrode current collector.

According to one embodiment of the present invention, the negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, for example, copper, stainless steel, aluminum, nickel, titanium, plastic. Surface treatment of carbon, copper or stainless steel with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used. In addition, the negative electrode current collector may typically have a thickness of 3 ㎛ to 500 ㎛, and like the positive electrode current collector, fine irregularities may be formed on the surface of the current collector to strengthen the bonding force of the negative electrode active material. For example, it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven materials.

According to one embodiment of the present invention, the negative electrode active material layer may optionally include a binder and a conductive material along with the negative electrode active material.

According to one embodiment of the present invention, a compound capable of reversible intercalation and deintercalation of lithium may be used as the negative electrode active material. Specific examples include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; Metallic compounds that can be alloyed with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, or Al alloy; Metal oxides that can dope and undope lithium, such as SiOβ (0<β<2), SnO ₂ , vanadium oxide, and lithium vanadium oxide; Alternatively, a composite containing the above-described metallic compound and a carbonaceous material, such as a Si-C composite or Sn-C composite, may be used, and any one or a mixture of two or more of these may be used. Additionally, a metallic lithium thin film may be used as the negative electrode active material. Additionally, the carbon material may include both low-crystalline carbon and high-crystalline carbon. Representative examples of low-crystalline carbon include soft carbon and hard carbon, and high-crystalline carbon includes amorphous, plate-shaped, flaky, spherical, or fibrous natural graphite, artificial graphite, and Kish graphite. graphite, pyrolytic carbon, mesophase pitch based carbonfiber, meso-carbon microbeads, mesophase pitches, and petroleum or coal tar pitch derived High-temperature calcined carbon such as cokes is a representative example. The negative electrode active material may be included in an amount of 80% to 99% by weight based on the total weight of the negative electrode active material layer.

According to one embodiment of the present invention, the binder of the negative electrode active material layer is a component that assists in bonding between the conductive material, the active material, and the current collector, and is typically contained in the amount of 0.1% by weight to 10% by weight based on the total weight of the negative electrode active material layer. is added. Examples of such binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, and polytetra. Examples include fluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, nitrile-butadiene rubber, fluorine rubber, and various copolymers thereof.

According to one embodiment of the present invention, the conductive material of the negative electrode active material layer is a component to further improve the conductivity of the negative electrode active material, and is contained in an amount of 10% by weight or less, preferably 5% by weight or less, based on the total weight of the negative electrode active material layer. may be added. These conductive materials are not particularly limited as long as they have conductivity without causing chemical changes in the battery, and examples include graphite such as natural graphite or artificial graphite; Carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; fluorinated carbon; Metal powders such as aluminum and nickel powder; Conductive whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives may be used.

According to one embodiment of the present invention, the negative electrode is manufactured by applying and drying a composition for forming a negative electrode active material layer prepared by dissolving or dispersing the negative electrode active material and optionally the binder and the conductive material in a solvent on the negative electrode current collector, or Alternatively, it can be manufactured by casting the composition for forming the negative electrode active material layer on a separate support and then peeling off the support and laminating the film obtained on the negative electrode current collector.

According to one embodiment of the present invention, the separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move. It can be used without particular restrictions as long as it is normally used as a separator in a lithium secondary battery, and in particular, it can be used for ion movement in the electrolyte. It is desirable to have low resistance and excellent electrolyte moisturizing ability. Specifically, porous polymer films, for example, porous polymer films made of polyolefin polymers such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, ethylene/hexene copolymer, and ethylene/methacrylate copolymer, or these. A laminated structure of two or more layers may be used. In addition, conventional porous nonwoven fabrics, for example, nonwoven fabrics made of high melting point glass fibers, polyethylene terephthalate fibers, etc., may be used. Additionally, a coated separator containing ceramic components or polymer materials may be used to ensure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure.

According to an embodiment of the present invention, the electrolyte may include an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, and a molten inorganic electrolyte that can be used when manufacturing a lithium secondary battery. It is not limited to these. As a specific example, the electrolyte may include an organic solvent and a lithium salt.

According to one embodiment of the present invention, the organic solvent may be used without particular limitation as long as it can serve as a medium through which ions involved in the electrochemical reaction of the battery can move. Specifically, the organic solvent includes ester solvents such as methyl acetate, ethyl acetate, γ-butyrolactone, and ε-caprolactone; Ether-based solvents such as dibutyl ether or tetrahydrofuran; Ketone-based solvents such as cyclohexanone; Aromatic hydrocarbon solvents such as benzene and fluorobenzene; Dimethylcarbonate (DMC), diethylcarbonate (DEC), methylethylcarbonate (MEC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC) ), carbonate-based solvents such as; Alcohol-based solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (R is a straight-chain, branched or ring-structured hydrocarbon group having 2 to 20 carbon atoms and may include a double bond aromatic ring or ether bond); Amides such as dimethylformamide; Dioxolanes such as 1,3-dioxolane; Alternatively, sulfolane, etc. may be used. Among these, carbonate-based solvents are preferable, and cyclic carbonates (e.g., ethylene carbonate or propylene carbonate, etc.) with high ionic conductivity and high dielectric constant that can improve the charging and discharging performance of the battery, and low-viscosity linear carbonate-based compounds ( For example, ethylmethyl carbonate, dimethyl carbonate, diethyl carbonate, etc.) are more preferable.

According to one embodiment of the present invention, the lithium salt can be used without particular limitation as long as it is a compound that can provide lithium ions used in lithium secondary batteries. Specifically, the anions of the lithium salt include F ^- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , N(CN) ₂ ^- , BF ₄ ^- , CF ₃ CF ₂ SO ₃ ^- , (CF ₃ SO ₂ ) ₂ N ^- , (FSO ₂ ) ₂ N ^- , CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- , (CF ₃ SO ₂ ) ₂ CH ^- , (SF ₅ ) ₃ C ^- , (CF ₃ SO ₂ ) ₃ C ^- , CF ₃ (CF ₂ ) ₇ SO ₃ ^- , CF ₃ CO ₂ ^- , CH ₃ CO ₂ ^- , SCN ^- , and (CF ₃ CF ₂ SO ₂ ) ₂ N ^- It may be at least one selected from the group consisting of, The lithium salt is LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAl0 ₄ , LiAlCl ₄ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN(C ₂ F ₅ SO ₃ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN(CF ₃ SO ₂ ) ₂ , LiCl, LiI, or LiB(C ₂ O ₄ ) ₂ may be used. The concentration of the lithium salt is preferably used within the range of 0.1 M to 2.0 M. When the concentration of lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so excellent electrolyte performance can be achieved and lithium ions can move effectively.

According to one embodiment of the present invention, in addition to the electrolyte components, the electrolyte contains halo such as difluoroethylene carbonate for the purpose of improving battery life characteristics, suppressing battery capacity reduction, and improving battery discharge capacity. Alkylene carbonate compounds, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexanoic acid triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazoli One or more additives such as dinon, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxy ethanol, or aluminum trichloride may be further included. At this time, the additive may be included in an amount of 0.1% to 5% by weight based on the total weight of the electrolyte.

The lithium secondary battery containing the exterior material for secondary batteries according to the present invention adsorbs gases generated during charging and discharging, and prevents seal failure of the exterior material for secondary batteries due to an increase in the internal pressure of the secondary battery, thereby exhibiting excellent stability, making it suitable for use in mobile phones. , It is useful in the field of portable devices such as laptop computers and digital cameras, and electric vehicles such as hybrid electric vehicles (HEV) and electric vehicles (EV).

The lithium secondary battery according to the present invention can not only be used in battery cells used as a power source for small devices, but can also be preferably used as a unit cell in medium to large-sized battery modules containing multiple battery cells.

Accordingly, according to one embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided.

According to one embodiment of the present invention, the battery module or battery pack includes a power tool; Electric vehicles, including electric vehicles (EV), hybrid electric vehicles, and plug-in hybrid electric vehicles (PHEV); Alternatively, it can be used as a power source for any one or more mid- to large-sized devices among power storage systems.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement it. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

Manufacturing example

Manufacturing Example 1

80 parts by weight of trimethylolpropane triglycidyl ether (Kukdo Chemical, YH-300) as a multifunctional epoxy compound and 20 parts by weight of polyethyleneimine (Sigma Aldrich, PEI) as an amine compound were sufficiently mixed, and the mixture was incubated at 90°C. Carbon dioxide adsorbent 1 was prepared by reacting in an oven for 5 hours.

Production example 2

In Preparation Example 1, trimethylolpropane triglycidyl ether (Kukdo Chemical, YH-300) was mixed at 90 parts by weight instead of 80 parts by weight, and polyethyleneimine (Sigma Aldrich, PEI) was mixed at 10 parts by weight instead of 20 parts by weight. Carbon dioxide adsorbent 2 was prepared in the same manner as Preparation Example 1 except that.

Production example 3

In Preparation Example 1, except that 20 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol (Sigma Aldrich, DMP30) was mixed as the amine compound instead of 20 parts by weight of polyethyleneimine (Sigma Aldrich, PEI). Carbon dioxide adsorbent 3 was prepared in the same manner as Preparation Example 1.

Comparative Manufacturing Example 1

In Preparation Example 1, trimethylolpropane triglycidyl ether (Kukdo Chemical, YH-300) was mixed at 20 parts by weight instead of 80 parts by weight, and polyethyleneimine (Sigma Aldrich, PEI) was mixed at 80 parts by weight instead of 20 parts by weight. Carbon dioxide adsorbent 4 was prepared in the same manner as Preparation Example 1 except that.

Comparative Manufacturing Example 2

In Preparation Example 1, trimethylolpropane triglycidyl ether (Kukdo Chemical, YH-300) was mixed at 95 parts by weight instead of 80 parts by weight, and polyethyleneimine (Sigma Aldrich, PEI) was mixed at 5 parts by weight instead of 20 parts by weight. Carbon dioxide adsorbent 5 was prepared in the same manner as Preparation Example 1 except that.

Comparative Manufacturing Example 3

In Preparation Example 1, instead of 80 parts by weight of trimethylolpropane triglycidyl ether (Kukdo Chemical, YH-300), which is a multifunctional epoxy compound, 80 parts by weight of butyl glycidyl ether (Kukdo Chemical, BGE), which is a monofunctional epoxy compound, was used. Carbon dioxide adsorbent 6 was prepared in the same manner as Preparation Example 1 except that the parts were mixed.

Examples and Comparative Examples

Example 1

Polypropylene (LG Chemical, MH1700) and carbon dioxide adsorbent 1 obtained in Preparation Example 1 were added to a stirrer (Harbin Harp Electrical Technology, RM-200C) at a weight ratio of 8:2, and then stirred at 170°C for 30 minutes. By mixing, polyolefin-based composite 1 was obtained in which polypropylene formed a continuous phase and carbon dioxide adsorbent 1 formed a dispersed phase.

Example 2

In Example 1, the same method as Example 1 was performed, except that carbon dioxide adsorbent 2 obtained in Preparation Example 2 was added instead of carbon dioxide adsorbent 1 obtained in Preparation Example 1, and polypropylene was continuously A phase was formed, and polyolefin-based composite 2, in which the carbon dioxide adsorbent 2 formed a dispersed phase, was obtained.

Example 3

In Example 1, the same method as Example 1 was performed, except that carbon dioxide adsorbent 3 obtained in Preparation Example 3 was added instead of carbon dioxide adsorbent 1 obtained in Preparation Example 1, and polyethylene was in the continuous phase. was formed, and polyolefin-based composite 3 in which carbon dioxide adsorbent 3 formed a dispersed phase was obtained.

Comparative Example 1

In Example 1, the same method as Example 1 was carried out, except that carbon dioxide adsorbent 4 obtained in Comparative Preparation Example 1 was added instead of carbon dioxide adsorbent 1 obtained in Preparation Example 1, and polypropylene was Polyolefin-based composite 4, in which a continuous phase was formed and the carbon dioxide adsorbent 4 formed a dispersed phase, was obtained.

Comparative Example 2

In Example 1, the carbon dioxide adsorbent 5 obtained in Comparative Preparation Example 2 was added instead of the carbon dioxide adsorbent 1 obtained in Preparation Example 1, but the carbon dioxide adsorbent was used in the same manner as in Example 1. 5 was in a liquid state rather than a solid state, making it impossible to manufacture polyolefin-based composite 5.

Comparative Example 3

In Example 1, carbon dioxide adsorbent 6 was prepared in the same manner as in Example 1, except that carbon dioxide adsorbent 6 obtained in Comparative Preparation Example 3 was added instead of carbon dioxide adsorbent 1 obtained in Preparation Example 1. Polyolefin-based composite 6, which formed this dispersed phase, was obtained.

Experiment example

Experimental Example 1: Evaluation of reactivity of carbon dioxide adsorbent

With respect to the carbon dioxide adsorbents 1 to 6 prepared in Preparation Examples 1 to 3 and Comparative Preparation Examples 1 to 3, after completion of the reaction, if the carbon dioxide adsorbent obtained in the oven is in a solid state, ○, if it is in a liquid state or is not completely solidified, the carbon dioxide adsorbent If there are components that come off, it is evaluated as X and is shown in Table 1 below.

division Manufacturing Example 1 Production example 2 Production example 3 Comparative Manufacturing Example 1 Comparative Manufacturing Example 2 Comparative Manufacturing Example 3 reactivity ○ ○ ○ ○ Ⅹ ○

As shown in Table 1, it was confirmed that carbon dioxide adsorbents 1 to 3 prepared in Preparation Examples 1 to 3 were all obtained in a solid state.

On the other hand, it was confirmed that the carbon dioxide adsorbent 5 prepared in Comparative Preparation Example 2, which contained a very excessive amount of a multifunctional epoxy compound and a very small amount of an amine compound, was obtained in a liquid state because sufficient curing did not proceed, and accordingly, the polyolefin Manufacturing the system composite itself was impossible.

Experimental Example 2: Carbon dioxide adsorption evaluation

The carbon dioxide adsorption properties of polyolefin-based composites 1 to 6 prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated in the following manner and are shown in Table 2 below.

* Carbon dioxide adsorption (% by volume): Three sides of an aluminum pouch (manufactured by DNP, EL408PH, 500) cut to a size of 10 cm x 10 cm were sealed to form a pouch-shaped pouch with one side open. Afterwards, 10 g of the polyolefin-based composite prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were placed in the pouch, carbon dioxide was injected to the maximum injectable content in the pouch, and the remaining one side was sealed to completely seal. A pouch was produced. After the completely sealed pouch was left at 60° C. for 24 hours, gas adsorption was calculated according to Equation 1 below. At this time, as a reference example, a pouch was manufactured in which carbon dioxide was injected and sealed without adding any of the polyolefin-based composites prepared in Examples 1 to 3 and Comparative Examples 1 to 3.

[Equation 1]

Carbon dioxide adsorption (volume %) = (Pouch volume after left at 60°C for 24 hours/Pouch volume sealed immediately after carbon dioxide injection) Ⅹ 100

division Reference example Example Comparative example One 2 3 One 2 3 carbon dioxide adsorption
(volume%) 97.3 5.0 4.8 4.5 98.0 N.A. 93.0

As shown in Table 2, it was confirmed that the pouches containing polyolefin-based composites 1 to 3 according to the present invention adsorbed carbon dioxide and exhibited a very high volume reduction rate.

On the other hand, in the case of Comparative Example 1 including carbon dioxide adsorbent 4 prepared by mixing an excessive amount of an amine compound compared to the multifunctional epoxy compound in the polyolefin-based composite, the activating group present in the carbon dioxide adsorbent due to excessive reaction between the multifunctional epoxy compound and the amine compound It was confirmed that there was no significant difference from the reference example due to the decrease.

In addition, in the case of Comparative Example 2, the production of the polyolefin-based composite itself was impossible, and in the case of Comparative Example 3, which used a monofunctional epoxy compound rather than a multifunctional epoxy compound, the activator present in the carbon dioxide adsorbent was not sufficient, resulting in a significant decrease in carbon dioxide adsorption. It was confirmed that it did not show improvement.

From these results, The carbon dioxide adsorbent of the present invention is contained in a dispersed form within the polyolefin-based composite used in the inner skin of the secondary battery exterior material, so a separate support such as a carrier, capsule, etc. is not required. The carbon dioxide adsorbent is coated on the secondary battery exterior material, or It was confirmed that stability can be improved by adsorbing gases generated during charging and discharging of secondary batteries, without requiring a separate space for attachment, and preventing seal failure of secondary battery exterior materials due to increased internal pressure of secondary batteries. I was able to.

Claims (10)

50% by weight or more and 94% by weight or less of the portion derived from a multifunctional epoxy compound containing two or more epoxy groups; and 6% by weight or more and 50% by weight or less of the amine compound derived portion,
The multifunctional epoxy compound-derived portion and the amine compound-derived portion simultaneously contain an activating group represented by the following formula (1),
Carbon dioxide adsorbent in solid state:
[Formula 1]

In Formula 1,
R ¹ is the remainder of a multifunctional epoxy compound containing two or more epoxy groups,
R ² to R ⁴ are the remainder of the amine compound. According to paragraph 1,
The carbon dioxide adsorbent contains 80% by weight or more and 90% by weight or less of a portion derived from a multifunctional epoxy compound containing two or more epoxy groups; And a carbon dioxide adsorbent containing 10% by weight or more and 20% by weight or less of an amine compound derived portion. According to paragraph 1,
A carbon dioxide adsorbent wherein the amine compound is at least one selected from the group consisting of primary amines, secondary amines, and tertiary amines. According to paragraph 1,
R ¹ is the remainder of a multifunctional epoxy compound containing 3 or more epoxy groups,
A carbon dioxide adsorbent wherein R ² to R ⁴ are each independently the remainder of one or more amine compounds selected from the group consisting of primary amines, secondary amines and tertiary amines. According to paragraph 1,
A carbon dioxide adsorbent wherein the molar ratio of the epoxy group derived from the multifunctional epoxy compound and the epoxy group to the amine compound:amine compound is 3 to 100:1. According to paragraph 1,
A carbon dioxide adsorbent wherein the activator reacts with carbon dioxide to form a cyclic carbonate group. Mixing 50 to 94 parts by weight of a polyfunctional epoxy compound containing two or more epoxy groups and 6 to 50 parts by weight of an amine compound for a total of 100 parts by weight of the polyfunctional epoxy compound and the amine compound ( S10); and
A carbon dioxide adsorbent manufacturing method comprising the step (S20) of reacting the mixture mixed in step (S10) at a temperature of 50 ℃ or more and 150 ℃ or less. In clause 7,
The method of producing a carbon dioxide adsorbent wherein the step (S20) is carried out for 0.5 hours or more and 24 hours or less. A polyolefin comprising not less than 60% by weight but not more than 90% by weight of the continuous phase and not less than 10% by weight but not more than 40% by weight of the dispersed phase, wherein the continuous phase includes a polyolefin-based resin, and the dispersed phase includes the carbon dioxide adsorbent according to claim 1. system complex. An exterior material for a secondary battery comprising the polyolefin-based composite according to claim 9 in the inner skin.