KR-20260063464-A - COMPOSITE ELECTROLYTE, BATTERY AND MANUFACTURING METHOD OF COMPOSITE ELECTROLYTE

KR20260063464AKR 20260063464 AKR20260063464 AKR 20260063464AKR-20260063464-A

Abstract

According to the present disclosure, a composite electrolyte capable of simultaneously exhibiting a suitable electrolyte impregnation amount, high ion conductivity, and heat resistance, and a battery capable of simultaneously ensuring safety and performance comprises: a substrate layer; and an active layer disposed on one or both sides of the substrate layer and comprising inorganic particles, a polymer component, and an electrolyte impregnated in said polymer component; wherein the active layer exhibits a first decomposition peak at a first temperature (T1) and a second decomposition peak at a second temperature (T2) higher than said second temperature during differential thermal gravitational analysis (DTG), and the range of said second temperature and the range of the difference (T2-T1) between said second temperature and said first temperature can be controlled, and a method for easily manufacturing said composite electrolyte comprises: preparing a slurry comprising inorganic particles, a polymer, and a first solvent; preparing a coating structure on which said slurry is applied on one or both sides of the substrate layer; immersing said coating structure in a first tank; and immersing said coating structure in a second tank. and immersing the coating structure in an electrolyte; wherein the first step comprises the first solvent and the second solvent, the second step comprises the second solvent, and the solubility of the polymer in the first solvent may be higher than the solubility of the polymer in the second solvent.

Inventors

유인경
유태선
이경수

Assignees

주식회사 엘지화학

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (18)

Substrate layer; and An active layer disposed on one or both sides of the above substrate layer and comprising inorganic particles, a polymer component, and an electrolyte impregnated in the polymer component; Includes, The above active layer exhibits a first decomposition peak at a first temperature (T1) during differential thermal gravimetry (DTG) and a second decomposition peak at a second temperature (T2) higher than the second temperature. The above second temperature is 200 ℃ or higher, and A composite electrolyte in which the difference between the second temperature and the first temperature (T2-T1) is 110 ℃ or higher.
In Article 1, The above-mentioned first temperature is a composite electrolyte within the range of 90 ℃ to 150 ℃.
In Article 1, A composite electrolyte in which the ratio (IP2/IP1) of the intensity of the second decomposition peak (IP2) and the intensity of the first decomposition peak (IP2) is 0.5 or greater.
In Article 1, The above-mentioned inorganic particles comprise one or more types selected from the group consisting of lithium-containing metal oxides and lithium-non-containing metal oxides, forming a composite electrolyte.
In Paragraph 4, The above lithium-containing metal oxide is a composite electrolyte comprising one or more selected from the group consisting of lithium aluminum germanium phosphate (LAGP)-based compounds, lithium lanthanum zirconium oxide (LLZO)-based compounds, lithium aluminum titanium phosphate (LATP)-based compounds, lithium lanthanum zirconium tantalum oxide (LLZTO)-based compounds, lithium silicon titanium phosphate (LSTP)-based compounds, and lithium oxide.
In Paragraph 4, The above lithium-free metal oxide is a composite electrolyte comprising one or more selected from the group consisting of zinc oxide (ZnO), calcium carbonate ( CaCO3 ), silicon dioxide ( SiO2 ), boehmite ( AlO (OH)), alumina ( Al2O3 ), and titanium dioxide ( TiO2 ).
In Article 1, The above polymer component is a composite electrolyte comprising one or more selected from the group consisting of polyvinylidene fluoride, poly(vinylidene fluoride-co-trichloroethylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene), poly(vinylidene fluoride-co-trifluoroethylene), poly(vinylidene fluoride-co-tetrafluoroethylene), poly(vinylidene fluoride-co-hexafluoropropylene), spandex, butyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, and polyvinyl acetate.
In Article 1, The above electrolyte is a composite electrolyte comprising a non-aqueous solvent and a lithium salt soluble in the non-aqueous solvent.
In Article 8, The above-mentioned non-aqueous solvent comprises one or more selected from the group consisting of carbonate-based solvents, ether-based solvents, ester-based solvents, and solvents containing polar functional groups, and The above lithium salt is a composite electrolyte comprising one or more selected from the group consisting of LiPF6 , LiBF4 , LiCl, LiBr, LiI , LiClO4 , LiAsF6 , LiCH3CO2 , LiCF3SO3, LiN( CF3SO2 ) 2 , and LiC( CF2SO2 ) 3 .
In Article 1, A composite electrolyte in which the thickness per layer of the active layer is within the range of 0.5 to 4 times the thickness of the substrate layer.
In Article 1, The above active layer is a composite electrolyte containing more of the inorganic particles than the polymer component.
In Article 1, The above substrate layer is a composite electrolyte comprising a polyolefin-based film.
It comprises an anode; a cathode; and a composite electrolyte disposed between the anode and the cathode, and The above composite electrolyte comprises a substrate layer; and an active layer disposed on one or both sides of the substrate layer, comprising inorganic particles, a polymer component, and an electrolyte impregnated in the polymer component, wherein the active layer exhibits a first decomposition peak at a first temperature (T1) and a second decomposition peak at a second temperature (T2) higher than the second temperature during differential thermogravimetric analysis. The above second temperature is 200 ℃ or higher, and A battery in which the difference between the second temperature and the first temperature (T2-T1) is 110 ℃ or more.
Preparing a slurry comprising inorganic particles, a polymer, and a first solvent; Preparing a coating structure in which the above slurry is applied to one or both sides of a substrate layer; Immerse the above coating structure in the first tank; Immersing the above coating structure in the second bath; and Immersing the above coating structure in an electrolyte; Includes, The above first article includes the first solvent and the second solvent, and The above Article 2 includes the above second solvent, and A method for preparing a composite electrolyte in which the solubility of the polymer in the first solvent is higher than the solubility of the polymer in the second solvent.
In Article 14, Immersion in the above-mentioned second section is a method for manufacturing a composite electrolyte in which the coating structure immersed in the above-mentioned first section is immersed in the second section.
In Article 14, A method for manufacturing a composite electrolyte, further comprising drying the coating structure immersed in the above-mentioned second clause.
In Article 16, Immersion in the above electrolyte is a method for manufacturing a composite electrolyte by immersing the dried coating structure in the above electrolyte.
In Article 14, The first solvent above includes NMP, and The above second solvent is a method for preparing a complex electrolyte containing water.

Description

Composite Electrolyte, Battery and Manufacturing Method of Composite Electrolyte The present disclosure relates to a composite electrolyte. The present disclosure relates to a battery. The present disclosure relates to a method for manufacturing a composite electrolyte. Inorganic coated separators are considered as one of the technologies to suppress the risk of battery ignition associated with the use of liquid electrolytes. An inorganic coated separator may comprise a porous substrate layer and inorganic particles coated on the outside of said porous substrate layer. The inorganic particles used in the inorganic coated separator can form a dense pore structure according to the interstitial volume. The pore structure may be related to the electrolyte impregnation amount. The electrolyte impregnation amount may be related to the amount of free electrolyte. The amount of free electrolyte may be related to the risk of battery ignition. In addition, it is required that the interfacial resistance of the separator be reduced and the ionic conductivity of the separator be increased. Figure 1 shows the thermogravimetric analysis results of the examples and comparative examples. Figure 2 is a side cross-sectional SEM image of the active layer of Example 1. Figure 3 is a side cross-sectional SEM image of the active layer of Example 2. Figure 4 is a side cross-sectional SEM image of the active layer of Comparative Example 1. The present disclosure is described in detail below. One embodiment of the present disclosure relates to a composite electrolyte. In the present disclosure, the composite electrolyte may comprise a polymer component impregnated with an electrolyte and inorganic particles composited therewith. In this respect, the composite electrolyte of the present disclosure differs from the structure of a conventional electrolyte and separator comprising a battery case housing an anode, a cathode, and a separator disposed between the anode and the cathode, and a liquid electrolyte injected therein. The composite electrolyte of the present disclosure may include a substrate layer; and an active layer disposed on one or both sides of the substrate layer. The active layer may comprise a polymer component and an electrolyte impregnated into the polymer component. As a result of impregnation by the electrolyte, the polymer component may swell. The swollen polymer component may have a gel phase. The active layer may further include inorganic particles. The inorganic particles participate in the transport of lithium ions, thereby improving the performance of the battery to which the composite electrolyte is applied. The above inorganic particles can impart heat resistance, heat insulation, heat absorption, etc. to the above composite electrolyte, thereby protecting the composite electrolyte from external mechanical and/or thermal stimuli. The above active layer can exhibit specific thermal behavior. Accordingly, the composite electrolyte can simultaneously exhibit an appropriate electrolyte impregnation amount, high ionic conductivity, and heat resistance. Specifically, when the active layer is subjected to Differential Thermal Gravimetry (DTG), it may exhibit peaks in at least two temperature ranges. The peak exhibited by the active layer may be a decomposition peak of the active layer. Additionally, the peak may represent a local minimum of the temperature versus weight change rate curve plotted during differential thermogravimetric analysis of the active layer. That is, when the active layer is subjected to differential thermogravimetric analysis, it may exhibit a first decomposition peak at a first temperature (T1) and a second decomposition peak at a second temperature (T2) that is higher than the first temperature. The fact that the active layer exhibits at least two decomposition peaks when subjected to differential thermogravimetric analysis may mean that the active layer decomposes in at least two temperature ranges. Furthermore, the fact that there are two or more temperature ranges in which decomposition peaks appear may mean that the active layer contains two or more materials with different thermal properties. The decomposition peak of the active layer and the temperature at which this decomposition peak appears can be determined according to the thermal characteristics of the components contained in the active layer. Specifically, the number of decomposition peaks of the active layer and the temperature at which these decomposition peaks appear can be determined according to the number and type of non-aqueous solvents contained in the electrolyte. That is, the electrolyte may contain two or more types of non-aqueous solvents. The electrolyte may contain two or more types of non-aqueous solvents with different boiling points, and this may affect the results of differential thermogravimetric analysis of the active layer. The present disclosure can control the second temperature and simultaneously control