US-12626954-B2 - Gel-type electrolyte composition for secondary battery and secondary battery including same

US12626954B2US 12626954 B2US12626954 B2US 12626954B2US-12626954-B2

Abstract

Provided is a gel-type electrolyte composition for a secondary battery and a secondary battery including the same, wherein the gel-type electrolyte composition includes a lithium salt, an organic solvent, a C1 to C5 alkoxy silane compound, and a multi-functional symmetrical compound having a (meth)acrylate group.

Inventors

Soojin Park
Hye Bin SON
Seoha NAM
Tae Sung Ha
Young Hwan Lee
Ji Hyun Park

Assignees

POSTECH Research and Business Development Foundation
GEV Co., Ltd.

Dates

Publication Date: 20260512
Application Date: 20230220
Priority Date: 20220331

Claims (7)

1 . A gel-type electrolyte composition for a secondary battery, the gel-type electrolyte composition comprising: a lithium salt; an organic solvent; a C1 to C5 alkoxy silane compound; and a multi-functional symmetrical compound having a (meth)acrylate group, wherein the multi-functional symmetrical compound comprises four to eight (meth)acrylate groups, the alkoxy silane compound and the multi-functional symmetrical compound are included at a weight ratio of 0.1:99.9 to 10:90, and the gel-type electrolyte composition is gelled by an irradiation of an electron beam.
2 . The gel-type electrolyte composition of claim 1 , wherein the alkoxy silane compound comprises a (meth)acrylate group or an epoxy group.
3 . The gel-type electrolyte composition of claim 1 , wherein the alkoxy silane compound comprises 3-methacryloxypropyl methyldimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyldiethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, 2-(3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, or a combination thereof.
4 . The gel-type electrolyte composition of claim 1 , wherein the multi-functional symmetrical compound comprises pentaerythritol tetraacrylate, di(trimethylolpropane) tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, an acrylo POSS cage mixture, or a combination thereof.
5 . The gel-type electrolyte composition of claim 1 , wherein: the organic solvent is included in an amount of 75 wt % to 99 wt % based on the total amount of the gel-type electrolyte composition for a secondary battery; the alkoxy silane compound is included in an amount of 0.1 wt % to 20 wt % based on the total amount of the gel-type electrolyte composition for a secondary battery; and the multi-functional symmetrical compound is included in an amount of 0.5 wt % to 10 wt % based on the total amount of the gel-type electrolyte composition for a secondary battery.
6 . The gel-type electrolyte composition of claim 1 , wherein the electron beam is irradiated in an irradiation dose of 3 kGy to 40 kGy.
7 . A secondary battery comprising: a positive electrode; a negative electrode; a separator positioned between the positive electrode and the negative electrode; and the gel-type electrolyte composition of claim 1 .

Description

BACKGROUND 1. Field Embodiments relate to a gel-type electrolyte composition for a secondary battery and a secondary battery including the same. 2. Description of the Related Art Lithium-ion secondary batteries are currently used in various devices to provide convenience to the extent that the Nobel Prize in Chemistry has been awarded in the field thereof. In addition, the electric vehicle market is greatly increasing due to the need for eco-friendly energy according to decarbonization policies. However, recently, a stability issue has emerged due to an ignition limitation of electric vehicles to which secondary batteries are applied. Liquid electrolytes are a major cause of explosion and ignition, and various next-generation batteries are being developed to solve this limitation. When a gel-type electrolyte is used as an alternative method of improving the safety of secondary batteries, there is an advantage in that leakage may be reduced and gas generation may be suppressed. However, due to the difficulty of commercialization, liquid electrolyte-based secondary batteries are still used. Various types of energy may be used for gelation to produce a gel-type electrolyte. For example, curing may be performed through 1) UV, 2) thermal-curing, and 3) radiation energy. In the case of UV and thermal-curing, a separate initiator should be included due to low energy, so that there is a disadvantage in that cell performance may be degraded due to the initiator. On the contrary, when radiation energy is used, there is an advantage in that curing may be achieved without an initiator. In addition, the radiation energy has an advantage of being able to be applied to the current industry at a large area and fast process speed. In addition, a lithium salt, which is an electrolyte used in a secondary battery, is vulnerable to moisture, so that moisture management is very important to suppress salt decomposition, and there are disadvantages in that the decomposed salt may destroy the surface of a positive electrode and additionally cause severe battery performance degradation at high temperatures. Various studies on electrolytes have been conducted to suppress such salt decomposition. However, in gel-type electrolytes, there are not sufficient studies conducted on these functional electrolytes. In addition, due to the low ion conductivity of a gel-type electrolyte, the gel-type electrolyte has lower electrochemical performance than a typical liquid electrolyte. In this regard, it is necessary to develop a multi-functional gel-type electrolyte precursor and apply process technology in order to secure interface properties and secure battery performance. SUMMARY An aspect of the present invention provides a gel-type electrolyte composition for a secondary battery having excellent stability and electrochemical performance. Another aspect of the present invention provides a secondary battery including the gel-type electrolyte composition. According to at least one of embodiments, a gel-type electrolyte composition for a secondary battery includes a lithium salt, an organic solvent, a C1 to C5 alkoxy silane compound, and a multi-functional symmetrical compound having a (meth)acrylate group. The alkoxy silane compound may include a (meth)acrylate group or an epoxy group. The alkoxy silane compound may include 3-methacryloxypropyl methyldimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyldiethoxysilane, 3-methacryloxypropyl triethoxysilane, 3-acryloxypropyl trimethoxysilane, 2-(3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-gylcidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-(trimethoxysilyl)propyl acrylate, 3-(trimethoxysilyl)propyl methacrylate, or a combination thereof. The multi-functional symmetric compound may include two to eight (meth)acrylate groups. The multi-functional symmetric compound may include pentaerythritol tetraacrylate, di(trimethylolpropane) tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, poly(ethylene glycol) diacrylate, poly(propylene glycol) diacrylate, bisphenol A glycerolate(1 glycerol/phenol) diacrylate, (C7H11O2)n(SiO1.5)n (wherein n is 1 to 100), (C6H9O2)n(SiO1.5)n (wherein n is 1 to 100), an acrylo POSS cage mixture, or a combination thereof. The alkoxy silane compound and the multi-functional symmetrical compound may be included at a weight ratio of 0.1:99.9 to 10:90. The organic solvent may be included in an amount of 75 wt % to 99 wt % based on the total amount of the gel-type electrolyte composition for a secondary battery, the alkoxy silane compound may be included in an amount of 0.1 wt % to 20 wt % based on the total amount of the gel-type electrolyte composition for a secondary battery, and the multi-functional symmetrical compound may be included in an amount of 0.5 wt % to 10 wt % based on the total amount of the gel-type electroly